Remove -Weffc++ from GCC

The "should be initialized in the member initialization list" is
incorrectly implemented on GCC.

https://stackoverflow.com/questions/14002454/can-i-ignore-the-gcc-warning-foom-bar-should-be-initialized-in-the-member-i

build_scripts/qt/compilers/clang-msvc.pri

@@ -12,6 +12,8 @@ include(clang-gcc-common-switches.pri)
 
 QMAKE_CXXFLAGS += -Wmost
 
+QMAKE_CXXFLAGS += -Weffc++
+
 #QMAKE_CXXFLAGS += -Wconversion
 #QMAKE_CXXFLAGS += -Wdouble-promotion
 #QMAKE_CXXFLAGS +=  -Wsign-conversion