Pressing escape on the plugin update dialog throws an exception

[matthewhorridge]

java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String
    at java.lang.String.compareTo(String.java:111) ~[na:1.8.0_25]
    at java.util.Arrays.binarySearch0(Arrays.java:2439) ~[na:1.8.0_25]
    at java.util.Arrays.binarySearch(Arrays.java:2379) ~[na:1.8.0_25]
    at org.protege.editor.core.ui.util.JOptionPaneEx.getReturnValue(JOptionPaneEx.java:111) ~[na:na]
    at org.protege.editor.core.ui.util.JOptionPaneEx.showConfirmDialog(JOptionPaneEx.java:60) ~[na:na]
    at org.protege.editor.core.update.PluginPanel.showDialog(PluginPanel.java:274) ~[na:na]
    at org.protege.editor.core.update.PluginManager.showUpdatesDialog(PluginManager.java:236) ~[na:na]
    at org.protege.editor.core.update.PluginManager.lambda$performCheckPlugins$5(PluginManager.java:218) ~[na:na]
    at org.protege.editor.core.update.PluginManager$$Lambda$36/636846013.run(Unknown Source) ~[na:na]
    at java.lang.Thread.run(Thread.java:745) ~[na:1.8.0_25]