ClearCase: Don't show Hijack button for dynamic view

The Hijack button (makeWriteableButton) should only
be shown for snapshot views.

Change-Id: I809981885d18b6057d82f73b5104b0f1041cd255
Reviewed-by: Orgad Shaneh <orgads@gmail.com>
Reviewed-by: Tobias Hunger <tobias.hunger@digia.com>

src/plugins/coreplugin/iversioncontrol.cpp

@@ -46,4 +46,9 @@ QString IVersionControl::vcsTopic(const QString &)
     return QString();
 }
 
+IVersionControl::OpenSupportMode IVersionControl::openSupportMode() const
+{
+    return NoOpen;
+}
+
 }