Revert "Issue #2603152 by alexpott, Fabianx, neclimdul: Fix PHP 7 testbot failures"

This reverts commit 5dc2bd06.

core/modules/system/src/Tests/System/DefaultMobileMetaTagsTest.php

@@ -44,11 +44,6 @@ public function testDefaultMetaTagsExist() {
    * Verifies that the default mobile meta tags can be removed.
    */
   public function testRemovingDefaultMetaTags() {
-    // @todo remove once PHP7 on Drupal CI has the fix.
-    if (version_compare(phpversion(), '7.0.0-dev') >= 0) {
-      // @see https://bugs.php.net/bug.php?id=70808
-      return;
-    }
     \Drupal::service('module_installer')->install(array('system_module_test'));
     $this->drupalGet('');
     foreach ($this->defaultMetaTags as $name => $metatag) {