When loading wxTextCtrl from XRC files, only call SetHint if the XRC specifies a hint. Otherwise an assert is triggered on multi-line text controls.

git-svn-id: https://svn.wxwidgets.org/svn/wx/wxWidgets/branches/WX_3_0_BRANCH@76669 c3d73ce0-8a6f-49c7-b76d-6d57e0e08775