Fix the whitespace issue in the message "Access Denied: Restricted File"

Summary:
Added whitespaces where missing in the restricted file message.

Closes T15270

Test Plan: Access a forbidden file. Check whitespaces in the error message.

Reviewers: O1 Blessed Committers, valerio.bozzolan, aklapper, waldyrious

Reviewed By: O1 Blessed Committers, valerio.bozzolan, waldyrious

Subscribers: aklapper, waldyrious, avivey, tobiaswiese, valerio.bozzolan, Matthew, Cigaryno

Tags: #ux

Maniphest Tasks: T15270

Differential Revision: https://we.phorge.it/D25419