Revert "Prevent race condition when generating TS cache (#1388)"

This reverts commit 91205c0.

Due to regression described in:
- https://jira.ez.no/browse/EZP-29901
- #1409
- #1388 (comment)

lib/ezi18n/classes/eztstranslator.php

@@ -218,10 +218,6 @@ function loadTranslationFile( $locale, $filename, $requestedContext )
                                 $this->Messages[$key] = $msg;
                             }
                         }
-                        else
-                        {
-                            $this->BuildCache = true;
-                        }
                         eZDebug::accumulatorStop( 'tstranslator_context_load' );
                     }
                 }