minor #21424 [Validator] Fix typo in Video constraint (wkania)

This PR was merged into the 7.4 branch.

Discussion
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[Validator] Fix typo in Video constraint

Commits
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bb56f0c [Validator] Fix typo in Video constraint

Author: javiereguiluz

reference/constraints/Video.rst

@@ -298,7 +298,7 @@ The message displayed if the video file contains multiple video streams.
 
 **type**: ``string`` **default**: ``The size of the video could not be detected.``
 
-The message displayed if ffprobe cannot detect the dimensions of the video.
+The message displayed if ``ffprobe`` cannot detect the dimensions of the video.
 
 ``unsupportedCodecMessage``
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~