qt4: remove ObjC++ hacks

This should fix the build with recent automake (fix #6911).
(cherry picked from commit fc55e4a1df2e691c73a28c6d6bc18143d60b97de)

modules/gui/qt4/Modules.am

@@ -12,7 +12,7 @@
 
 AUTOMAKE_OPTIONS = subdir-objects
 MOSTLYCLEANFILES = $(UIH)
-SUFFIXES = .ui .h .hpp .moc.cpp .mm
+SUFFIXES = .ui .h .hpp .moc.cpp
 
 nodist_SOURCES_qt4 = \
 		main_interface.moc.cpp \
@@ -245,9 +245,6 @@ endif
 	$(AM_V_at)sed -e 's/Q_(\"_(\\\"\(.*\)\\\")"/Q_("\1"/' $@.tmp >$@
 	$(AM_V_at)rm -f $@.tmp
 
-.mm.lo: 
-	$(top_builddir)/libtool --verbose --mode=compile $(CXX) $(objcxxflags) -DQ_WS_MAC -I$(top_srcdir)/include -I$(top_builddir)/include -I$(top_builddir) $(CXXFLAGS_qt4) -c $< -o $@ 
-
 SOURCES_qt4 = 	qt4.cpp \
 		menus.cpp \
 		main_interface.cpp \
@@ -317,10 +314,6 @@ SOURCES_qt4 = 	qt4.cpp \
 		util/buttons/DeckButtonsLayout.cpp \
 		util/buttons/RoundButton.cpp
 
-if HAVE_DARWIN
-SOURCES_qt4 +=  util/searchlineedit_mac.mm
-endif
-
 if HAVE_WIN32
 SOURCES_qt4 += main_interface_win32.cpp
 endif