minor symfony#16644 [travis] Disable xdebug on PHP7 (nicolas-grekas)

This PR was merged into the 2.3 branch.

Discussion
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[travis] Disable xdebug on PHP7

| Q             | A
| ------------- | ---
| Bug fix?      | no
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | -
| License       | MIT
| Doc PR        | -

Commits
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dfda5ce [travis] Disable xdebug on PHP7

Author: nicolas-grekas

.travis.yml

@@ -36,7 +36,7 @@ before_install:
     - echo "memory_limit = -1" >> $INI_FILE
     - echo "session.gc_probability = 0" >> $INI_FILE
     - if [ "$deps" != "skip" ]; then composer self-update; fi;
-    - if [[ "$TRAVIS_PHP_VERSION" = 5.* ]]; then phpenv config-rm xdebug.ini; fi;
+    - if [[ "$TRAVIS_PHP_VERSION" != "hhvm" ]]; then phpenv config-rm xdebug.ini; fi;
     - if [[ "$TRAVIS_PHP_VERSION" = 5.* ]]; then echo "extension = mongo.so" >> $INI_FILE; fi;
     - if [[ "$TRAVIS_PHP_VERSION" = 5.* ]]; then echo "extension = memcache.so" >> $INI_FILE; fi;
     - if [[ "$TRAVIS_PHP_VERSION" = 5.* ]]; then (echo yes | pecl install -f apcu-4.0.7 && echo "apc.enable_cli = 1" >> $INI_FILE) || echo "Let's continue without apcu extension"; fi;