luci-base: rename mii-tool object property to mii_tool

otherwise ucode function call breaks with:

RPC call to luci/getInitList failed with error -32000: Object not found

Follow-up fix to ab15b5e

Signed-off-by: Paul Donald <newtwen+github@gmail.com>

modules/luci-base/root/usr/share/rpcd/ucode/luci

@@ -197,7 +197,7 @@ const methods = {
 				firewall4:  access('/sbin/fw4') == true,
 				opkg:       access('/bin/opkg') == true,
 				bonding:    access('/sys/module/bonding'),
-				mii-tool:   access('/usr/sbin/mii-tool'),
+				mii_tool:   access('/usr/sbin/mii-tool'),
 				offloading: access('/sys/module/xt_FLOWOFFLOAD/refcnt') == true || access('/sys/module/nft_flow_offload/refcnt') == true,
 				br2684ctl:  access('/usr/sbin/br2684ctl') == true,
 				swconfig:   access('/sbin/swconfig') == true,

modules/luci-mod-network/htdocs/luci-static/resources/tools/network.js

@@ -869,7 +869,7 @@ return baseclass.extend({
 		o.depends('type', 'bonding');
 
 		o = this.replaceOption(s, 'devadvanced', form.ListValue, 'monitor_mode', _('Link monitoring mode'),
-			!L.hasSystemFeature('mii-tool') ? '<a href="' + L.url("admin", "system", "package-manager", "?query=mii-tool") + '">'+
+			!L.hasSystemFeature('mii_tool') ? '<a href="' + L.url("admin", "system", "package-manager", "?query=mii-tool") + '">'+
 			 _('Install %s').format('<code>mii-tool</code>') + '</a>' : null);
 		o.default = '';
 		o.value('arp', _('ARP link monitoring'));