Fix test to avoid network usage

tests/Composer/Test/Fixtures/installer/repositories-priorities4.test

@@ -25,8 +25,17 @@ Packages found in a higher priority repository take precedence even if they are
             ]
         },
         {
-            "type": "composer",
-            "url": "https://repo.packagist.org"
+            "type": "package",
+            "package": [
+                {
+                    "name": "ruflin/elastica",
+                    "version": "2.0.0"
+                },
+                {
+                    "name": "ruflin/elastica",
+                    "version": "2.0.1"
+                }
+            ]
         }
     ],
     "require": {
@@ -43,7 +52,7 @@ Your requirements could not be resolved to an installable set of packages.
 
   Problem 1
     - Root composer.json requires friendsofsymfony/elastica-bundle dev-foobar-master -> satisfiable by friendsofsymfony/elastica-bundle[dev-foobar-master].
-    - friendsofsymfony/elastica-bundle dev-foobar-master requires ruflin/elastica 2.* -> satisfiable by ruflin/elastica[2.0.0, ..., 2.3.3] from composer repo (https://repo.packagist.org) but ruflin/elastica[dev-outdated-branch] from package repo (defining 1 package) has higher repository priority. The packages with higher priority do not match your constraint and are therefore not installable. See https://getcomposer.org/repoprio for details and assistance.
+    - friendsofsymfony/elastica-bundle dev-foobar-master requires ruflin/elastica 2.* -> satisfiable by ruflin/elastica[2.0.0, 2.0.1] from package repo (defining 2 packages) but ruflin/elastica[dev-outdated-branch] from package repo (defining 1 package) has higher repository priority. The packages with higher priority do not match your constraint and are therefore not installable. See https://getcomposer.org/repoprio for details and assistance.
 
 --EXPECT--
 --EXPECT-EXIT-CODE--