minor #13386 [Debug] add missing conflict dep rules (nicolas-grekas)

This PR was merged into the 2.3 branch.

Discussion
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[Debug] add missing conflict dep rules

| Q             | A
| ------------- | ---
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | #13381
| License       | MIT
| Doc PR        | -

Commits
-------

a4be610 [Debug] add missing conflict dep rules

src/Symfony/Component/Debug/composer.json

@@ -18,6 +18,9 @@
     "require": {
         "php": ">=5.3.3"
     },
+    "conflict": {
+        "symfony/http-kernel": ">=2.3,<2.3.24|~2.4.0|>=2.5,<2.5.9|>=2.6,<2.6.2"
+    },
     "require-dev": {
         "symfony/http-kernel": "~2.3.24|~2.5.9|~2.6,>=2.6.2",
         "symfony/http-foundation": "~2.1"