print/ghostscript7: This is not jobs safe

This port is doing some king of crazy delete/copy thing with gconfig.h
and there's a race where it gets used before it's copied.  Mark this
port unsafe until further notice; it has failed on me a couple of times.

tailored log:
  rm -f ./obj/../soobj/gconfig.h
  cp ./obj/../soobj/gconfxx.h ./obj/../soobj/gconfig.h
  rm -f ./obj/../soobj/gconfig.h
  cp ./src/gconf.c ./obj/../soobj/gconfig.cOA
  cp ./obj/../soobj/gconfxx.h ./obj/../soobj/gconfig.h
  [snip]
  cp ./obj/../soobj/gconfxx.h ./obj/../soobj/gconfig.h
  In file included from ./obj/../soobj/iconfig.c:43:0:
  ./src/gconf.h:34:23: fatal error: ./obj/../soobj/gconfig.h: No such file
    or directory
  compilation terminated.

print/ghostscript7/Makefile

@@ -51,6 +51,8 @@ LDFLAGS+=	${XLDFLAGS}
 XLDFLAGS=	-lpthread -L${LOCALBASE}/lib -L${WRKSRC}/gimp-print
 PLIST_SUB=	GS_VERSION="${PORTVERSION}"
 
+MAKE_JOBS_UNSAFE=	yes
+
 OPTIONS_DEFINE=	X11 DOCS A4SIZE
 OPTIONS_DEFAULT=X11 DOCS A4SIZE
 NO_OPTIONS_SORT=yes