Remove .sql3 hacks from Differential

Summary:
See T178. D372 is the correct fix for this problem, hardcoding .sql3 is not.

Test Plan:
This code should be unreachable after T178 since these files will always be
marked as binary.

Reviewed By: tuomaspelkonen
Reviewers: tuomaspelkonen
CC: elgenie, aran, tuomaspelkonen
Differential Revision: 373

src/applications/differential/parser/changeset/DifferentialChangesetParser.php

@@ -879,10 +879,6 @@ EOSYNTHETIC;
         $shield = $this->renderShield(
           "This file has a very large number of changes ({$lines} lines).",
           true);
-      } else if (preg_match('/\.sql3$/', $this->changeset->getFilename())) {
-        $shield = $this->renderShield(
-          ".sql3 files are hidden by default.",
-          true);
       }
     }