development/gforth: Disable parallel build.

Signed-off-by: B. Watson <yalhcru@gmail.com>

Signed-off-by: Willy Sudiarto Raharjo <willysr@slackbuilds.org>

development/gforth/gforth.SlackBuild

@@ -64,6 +64,9 @@ find -L . \
  \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
   -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
 
+# Disable parallel building otherwise build fails
+MAKEFLAGS=-j1
+
 # Fix old-style flag
 sed -i "s/-m486/-mtune=i486/g" configure.in