Make removing subproject work when not added to targets.
Make removing subproject work when not added to targets.

iosdevzone/XcodeEditor,cezheng/XcodeEditor,cezheng/XcodeEditor,khanhtbh/XcodeEditor,khanhtbh/XcodeEditor,andyvand/XcodeEditor,appsquickly/XcodeEditor,JoelGerboreLaser/XcodeEditor,service2media/XcodeEditor,JoelGerboreLaser/XcodeEditor,appsquickly/XcodeEditor,appsquickly/XcodeEditor