Make project_dir local so it doesn't clobber other variables.

Author: seth@seth-ec-laptop

virtualenvwrapper.sh

@@ -918,7 +918,7 @@ function cdproject {
     virtualenvwrapper_verify_active_environment || return 1
     if [ -f "$VIRTUAL_ENV/$VIRTUALENVWRAPPER_PROJECT_FILENAME" ]
     then
-        project_dir=$(cat "$VIRTUAL_ENV/$VIRTUALENVWRAPPER_PROJECT_FILENAME")
+        local project_dir=$(cat "$VIRTUAL_ENV/$VIRTUALENVWRAPPER_PROJECT_FILENAME")
         if [ ! -z "$project_dir" ]
         then
             cd "$project_dir"