minor #9868 Fix the page title for the mbstring polyfill (stof)

This PR was merged into the 4.1 branch.

Discussion
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Fix the page title for the mbstring polyfill

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Commits
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debea66 Fix the page title for the mbstring polyfill

Author: javiereguiluz

components/polyfill_mbstring.rst

@@ -3,8 +3,8 @@
     single: Mbstring
     single: Components; Polyfill
 
-The Symfony Polyfill / Intl Mbstring Component
-==============================================
+The Symfony Polyfill / Mbstring Component
+=========================================
 
     This component provides a partial, native PHP implementation for the
     ``mbstring`` PHP extension.