Prevent to use GNU sed extension feature

It is GNU sed extension feature to use "\n" in insert string,
so it should be replaced with portable way.

This resolves bug 2986.

Signed-off-by: OBATA Akio <obache@wizdas.com>
(cherry picked from commit eee820646d)

qtinterface/tmoc.cmake

@@ -12,7 +12,10 @@ if [ -f @BIN_INSTALL_DIR@/tqt-replace-stream ]; then
 		out_file="$3"
 		@BIN_INSTALL_DIR@/tqt-replace-stream "${input_file}" | \
 	        @MOC_EXECUTABLE@ | \
-	        sed "/#include <qmetaobject.h>/ i #undef QT_NO_COMPAT\n#include \"${input_file}\"" \
+	        sed "/#include <qmetaobject.h>/ i\\
+#undef QT_NO_COMPAT\\
+#include \"${input_file}\"\\
+" \
 		> "${out_file}"
 	fi
 else