Use open command to run the GUI unit test on Mac build slave.

Running the application binary directly still doesn't work quite the same as
when it's opened from Finder (or executed using open) and some tests involving
event loops fail because of this.

Run it using open even if it means that we lose the detailed log output.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/trunk@66499 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775

build/buildbot/config/include/csleobuild.xml

@@ -30,7 +30,7 @@
                 export DYLD_LIBRARY_PATH=../lib
                 cd tests &&
                 ./test -t &&
-                ./test_gui.app/Contents/MacOS/test_gui -t
+                open ./test_gui.app
             </command>
         </copy-with-defaults>
     </test>