Fix X11 build option checkbox

Similar problem as PulseAudio, but even grosser.

src/conio/Common.gmake

@@ -56,9 +56,7 @@ ifndef win
    endif
   endif
  else
-  ifeq ($(os),darwin)
-   CIOLIB-MT_CFLAGS		+=  -DDISABLE_X11=1
-  endif
+  CIOLIB-MT_CFLAGS		+=  -DDISABLE_X11=1 -DNO_X
  endif
 else
  NO_X			 :=  1

src/conio/GNUmakefile

@@ -16,9 +16,7 @@ ifdef win
 else
  OBJS	+=	$(MTOBJODIR)$(DIRSEP)curs_cio$(OFILE)
 endif
-ifdef NO_X
- CFLAGS	+=	-DNO_X
-else
+ifndef NO_X
  OBJS	+=	$(MTOBJODIR)$(DIRSEP)x_events$(OFILE)
  OBJS	+=      $(MTOBJODIR)$(DIRSEP)x_cio$(OFILE)
  NEED_BITMAP := 1