Fix TranscodingStreamer for PHP 7.4 (#1189)

Passing the glue parameter after the pieces parameter when calling
implode is deprecated as of PHP 7.4.

This was the only remaining instance, all other implode calls already
use the correct parameter order.

app/Services/Streamers/TranscodingStreamer.php

@@ -44,7 +44,7 @@ public function stream(): void
             array_unshift($args, "-ss {$this->startTime}");
         }
 
-        passthru("$ffmpeg ".implode($args, ' '));
+        passthru("$ffmpeg ".implode(' ', $args));
     }
 
     public function setBitRate(int $bitRate): void