remove unused line

Author: miya0001

.travis.yml

@@ -39,7 +39,6 @@ matrix:
       env: WP_VERSION=latest
 
 before_install:
-  - phpenv config-rm xdebug.ini
   - |
     # Remove Xdebug for a huge performance increase:
     if [ -f ~/.phpenv/versions/$(phpenv version-name)/etc/conf.d/xdebug.ini ]; then