Increase test timeout

...it now matches the duration of another nearby timeout in the code, and it
happened to cause a parallel "make check" to sometimes fail on a slow MacBook.

Change-Id: If8bddb82a05c46637fdc2fcc3373411fcb37a466

sfx2/qa/complex/sfx2/UndoManager.java

@@ -179,7 +179,7 @@ public class UndoManager
         impl_clickButton( buttonModel );
         // the macro is executed asynchronously by the button, so wait at most 2 seconds for the callback to be
         // triggered
-        impl_waitFor( m_callbackCondition, 2000 );
+        impl_waitFor( m_callbackCondition, 20000 );
         // check the callback has actually been called
         assertTrue( "clicking the test button did not work as expected - basic script not called", m_callbackCalled );