generate_ui: adapt to upstream change in qtbase

Change 106487387d493dab934e19b33bfed55b8df62d67 in qtbase
removed a few ? true : false, some of them happened to be
in uic's generated code.

Adapt the generator.

Change-Id: I1c5aefef57e3d17aaef3c1eee4ce92730499b4df
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>