Fix lupdate-warnings in qqmlimport.cpp.
Fix lupdate-warnings in qqmlimport.cpp.

qqmlimport.cpp:738: Class 'QQmlImportsPrivate' lacks Q_OBJECT

Remove tr()-function and use QQmlImportDatabase::tr()
directly.

Change-Id: I3a1561c57a6ee90d271a6043b0175e17a7828666
Reviewed-by: Alan Alpert (Personal) <88b56286e35a5224392cc092099688d403c4217b@gmail.com>

jfaust/qtdeclarative,jfaust/qtdeclarative,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d,crobertd/qtdeclarative,corngood/qtdeclarative,corngood/qtdeclarative,jfaust/qtdeclarative,matthewvogt/qtdeclarative,corngood/qtdeclarative,qmlc/qtdeclarative,jfaust/qtdeclarative,jfaust/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,crobertd/qtdeclarative,crobertd/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,matthewvogt/qtdeclarative,mgrunditz/qtdeclarative-2d,crobertd/qtdeclarative,qmlc/qtdeclarative,corngood/qtdeclarative,crobertd/qtdeclarative,corngood/qtdeclarative,corngood/qtdeclarative,matthewvogt/qtdeclarative,qmlc/qtdeclarative,jfaust/qtdeclarative,crobertd/qtdeclarative,matthewvogt/qtdeclarative,corngood/qtdeclarative,qmlc/qtdeclarative,jfaust/qtdeclarative,mgrunditz/qtdeclarative-2d,qmlc/qtdeclarative,mgrunditz/qtdeclarative-2d,mgrunditz/qtdeclarative-2d,crobertd/qtdeclarative