ClearCaseSettings: initialize member

Change-Id: Ib43dbddd64bb179f65d25705757682f6a8088af0
Reviewed-by: Orgad Shaneh <orgads@gmail.com>

src/plugins/clearcase/clearcasesettings.cpp

@@ -70,7 +70,8 @@ ClearCaseSettings::ClearCaseSettings() :
     autoAssignActivityName(true),
     autoCheckOut(true),
     promptToCheckIn(false),
-    disableIndexer(false)
+    disableIndexer(false),
+    extDiffAvailable(false)
 {
 }