minor #12675 Change 4 to 5 in anticipation of future patch (ThomasGallet)

This PR was submitted for the master branch but it was merged into the 5.0 branch instead (closes #12675).

Discussion
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Change 4 to 5 in anticipation of future patch

#SymfonyHackathon

Commits
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076cb4a Change 4 to 5 in anticipation of future patch

Author: wouterj

setup/upgrade_patch.rst

@@ -1,7 +1,7 @@
 .. index::
     single: Upgrading; Patch Version
 
-Upgrading a Patch Version (e.g. 4.1.0 to 4.1.1)
+Upgrading a Patch Version (e.g. 5.0.0 to 5.0.1)
 ===============================================
 
 When a new patch version is released (only the last number changed), it is a