minor #11672 Remvove space before self-closing xml tag (OskarStark)

This PR was merged into the 4.2 branch.

Discussion
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Remvove space before self-closing xml tag

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Commits
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23091f8 Remvove space before self-closing xml tag

Author: OskarStark

security/impersonating_user.rst

@@ -222,7 +222,7 @@ be called:
 
                 <firewall name="main">
                     <!-- ... -->
-                    <switch-user role="CAN_SWITCH_USER" />
+                    <switch-user role="CAN_SWITCH_USER"/>
                 </firewall>
             </config>
         </srv:container>