Remove superfluous newlines as per PHPCBF

exceptions/generic/MDOutputBufferNotStarted.php

@@ -10,7 +10,6 @@
  * Custom exception class for non-existing files.
  */
 final class MDOutputBufferNotStarted extends Exception {
-
     /**
      * Error message.
      *
@@ -22,5 +21,4 @@ public function errorMessage() {
         return $errorMsg;
 
     }
-
 }