Revert "nx-X11/Makefile: pass down $(MFLAGS) to imake call, because... we probably want that. Likely."

This commit breaks compilation because if compiled without VERBOSE we
end up in imake -s -s xmakefile being called. See
ArcticaProject#1058 (comment)

As -s in imake defines and output file instead of the silencing the
output it is called wrong.

This reverts commit 72f11ee.

Adresses ArcticaProject#1058 (part 2)

Author: uli42

nx-X11/Makefile

@@ -70,7 +70,7 @@ xmakefile:
 	else \
 	    exit 0; \
 	fi
-	which $(IMAKE) 1>/dev/null && $(IMAKE_CMD) $(MFLAGS) -s xmakefile -DTOPDIR=$(TOP) -DCURDIR=$(CURRENT_DIR)
+	which $(IMAKE) 1>/dev/null && $(IMAKE_CMD) -s xmakefile -DTOPDIR=$(TOP) -DCURDIR=$(CURRENT_DIR)
 
 # don't allow any default rules in this Makefile
 .SUFFIXES: