Extension fails to load if limit of FSWatchers is reached

[dgolovin]

Sometimes ext fails to activate due to error, error to register watcher for file should not stop ext activation. The warning should be shown that automatic update for explorer is disabled due to limit of watchers reached.

Error: ENOSPC: System limit for number of file watchers reached, watch '/home/denis/.kube'
	at FSWatcher.<anonymous> (internal/fs/watchers.js:218)
	at Object.watch (fs.js:1525)
	at Function.watchFileForContextChange (/home/denis/p/vscode-openshift-tools/out/src/util/watch.js:17)
	at new OpenShiftExplorer (/home/denis/p/vscode-openshift-tools/out/src/explorer.js:43)
	at Function.getInstance (/home/denis/p/vscode-openshift-tools/out/src/explorer.js:69)
	at Object.<anonymous> (/home/denis/p/vscode-openshift-tools/out/src/openshift/openshiftItem.js:200)
	at Module._compile (internal/modules/cjs/loader.js:1125)
	at Object..js (internal/modules/cjs/loader.js:1155)
	at Module.load (internal/modules/cjs/loader.js:982)
	at internal/modules/cjs/loader.js:823
	at Function.<anonymous> (electron/js2c/asar_bundle.js:5)
	at Function.<anonymous> (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:103)
	at Function.<anonymous> (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:103)
	at Function._load (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:93)
	at Module.require (internal/modules/cjs/loader.js:1006)
	at require (internal/modules/cjs/helpers.js:88)
	at Object.<anonymous> (/home/denis/p/vscode-openshift-tools/out/src/openshift/cluster.js:26)
	at Module._compile (internal/modules/cjs/loader.js:1125)
	at Object..js (internal/modules/cjs/loader.js:1155)
	at Module.load (internal/modules/cjs/loader.js:982)
	at internal/modules/cjs/loader.js:823
	at Function.<anonymous> (electron/js2c/asar_bundle.js:5)
	at Function.<anonymous> (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:103)
	at Function.<anonymous> (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:103)
	at Function._load (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:93)
	at Module.require (internal/modules/cjs/loader.js:1006)
	at require (internal/modules/cjs/helpers.js:88)
	at Object.<anonymous> (/home/denis/p/vscode-openshift-tools/out/src/extension.js:21)
	at Module._compile (internal/modules/cjs/loader.js:1125)
	at Object..js (internal/modules/cjs/loader.js:1155)
	at Module.load (internal/modules/cjs/loader.js:982)
	at internal/modules/cjs/loader.js:823
	at Function.<anonymous> (electron/js2c/asar_bundle.js:5)
	at Function.<anonymous> (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:103)
	at Function.<anonymous> (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:103)
	at Function._load (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:93)
	at Module.require (internal/modules/cjs/loader.js:1006)
	at require (internal/modules/cjs/helpers.js:88)
	at Function.t [as __$__nodeRequire] (loader.js:1025)
	at m._loadCommonJSModule (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:103)
	at m._doActivateExtension (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:89)
	at m._activateExtension (/snap/code/67/usr/share/code/resources/app/out/vs/workbench/services/extensions/node/extensionHostProcess.js:89)
	at processTicksAndRejections (internal/process/task_queues.js:93)
onDidChangeNotification @ notificationsAlerts.ts:38