Fix OpenGL on Linux with Qt 5.5
Fix OpenGL on Linux with Qt 5.5

The XCB platform plugin now needs a plugin for the OpenGL backend

Change-Id: I5e7b296a0b645aec2a8d3ba80c53cb946e35e7f1
Reviewed-by: Laszlo Agocs <00c05606d635b5d8e1450a8536e4e2809abe4e80@theqtcompany.com>

xianian/qt-creator,martyone/sailfish-qtcreator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator,xianian/qt-creator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,martyone/sailfish-qtcreator,xianian/qt-creator