[gtk-osx: 28/48] Don't use envvar for regular file.

[John Ralls <jralls src gnome org>]

commit 17ac4d873d425fe7b05cd0aa96c9310259fbdae2
Author: John Ralls <jralls ceridwen us>
Date:   Sat Apr 13 14:30:41 2019 -0700

    Don't use envvar for regular file.

 gtk-osx-setup.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
---
diff --git a/gtk-osx-setup.sh b/gtk-osx-setup.sh
index 56a462f..31a6ec6 100755
--- a/gtk-osx-setup.sh
+++ b/gtk-osx-setup.sh
@@ -234,7 +234,8 @@ if test -z "$jhbuildrc_file" ; then
     curl -ks $BASEURL/jhbuildrc-gtk-osx -o "$config_dir/jhbuildrc"
 fi
 
-envvar JHBUILDRC_CUSTOM "$config_dir/jhbuildrc-custom"
+if test -z "$JHBUILDRC_CUSTOM"; then
+   JHBUILDRC_CUSTOM="$config_dir/jhbuildrc-custom"
 if test ! -e "$JHBUILDRC_CUSTOM" -a ! -e $HOME/.jhbuildrc-custom; then
    curl -ks $BASEURL/jhbuildrc-gtk-osx-custom-example -o $JHBUILDRC_CUSTOM
 fi