Nonsensical dependency to moc tool created in generated makefiles for Symbian

This part of moc.prf creates a dependency to the moc tool in Symbian makefiles:

unix:!no_mocdepend {
     moc_source.depends += $$first(QMAKE_MOC)
     moc_header.depends += $$first(QMAKE_MOC)
     !contains(TARGET, moc) { #auto build moc
         isEmpty(QMAKE_MOC_SRC):QMAKE_MOC_SRC = "$(QTDIR)/src/tools/moc"
    	 make_moc.target = $$first(QMAKE_MOC)
	     make_moc.commands = (cd $$QMAKE_MOC_SRC && $(MAKE))
	     QMAKE_EXTRA_TARGETS += make_moc
     }
}

In a Symbian platform build this dependency will fail because QTDIR is not fully present, and moc is actually exported to \epoc32\tools\.

The solution is to make the block above not active for Symbian, e.g. via

!symbian:unix:!no_mocdepend { ...

The dependency is introduced because Symbian is considered to be a unix platform due to OpenC