bug #13711 [FrameworkBundle] Check if templating is enabled. (jakzal)

This PR was merged into the 2.7 branch.

Discussion
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[FrameworkBundle] Check if templating is enabled.

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #13710
| License       | MIT
| Doc PR        | -

templating can be disabled.

Commits
-------

c75b276 [FrameworkBundle] Check if templating is enabled.

src/Symfony/Bundle/FrameworkBundle/DependencyInjection/Configuration.php

@@ -56,7 +56,8 @@ class Configuration implements ConfigurationInterface
             ->validate()
                 ->ifTrue(function ($v) { return !isset($v['assets']); })
                 ->then(function ($v) {
-                    if (!$v['templating']['assets_version']
+                    if (!isset($v['templating'])
+                        || !$v['templating']['assets_version']
                         && !count($v['templating']['assets_base_urls']['http'])
                         && !count($v['templating']['assets_base_urls']['ssl'])
                         && !count($v['templating']['packages'])