Merge pull request #562 from TGMPA/feature/minor-fix

Fix @SInCE tag of a filter.

class-tgm-plugin-activation.php

@@ -1443,7 +1443,7 @@ public function sanitize_key( $key ) {
 			/**
 			* Filter a sanitized key string.
 			*
-			* @since 3.0.0
+			* @since 2.5.0
 			*
 			* @param string $key     Sanitized key.
 			* @param string $raw_key The key prior to sanitization.