Fixed ambiguous sentence

Fixed sentence that created confusion: "A few libraries starting with symfony/ follow their versioning scheme." should contain "own"

Author: fridde

setup/upgrade_minor.rst

@@ -41,7 +41,7 @@ probably need to update the version constraint next to each library starting
               "...": "...",
 
               "...": "A few libraries starting with
-                      symfony/ follow their versioning scheme. You
+                      symfony/ follow their own versioning scheme. You
                       do not need to update these versions: you can
                       upgrade them independently whenever you want",
               "symfony/monolog-bundle": "^3.5",