Remove always-empty stderr log when stdout/stderr pipes are unavailable

When stdout or stderr is null, no listener has been registered yet,
so stderrChunks is always empty at that point. The ffmpeg output log
would always produce an empty string, so remove it.

Suggested by @dahlia in PR review.

Author: ntsklab

src/media.ts

@@ -103,9 +103,6 @@ export async function makeVideoScreenshot(
         logger.error(
           "Could not build pipes to ffmpeg, can't create a video screenshot",
         );
-        logger.error("ffmpeg output: {stderr}", {
-          stderr: Buffer.concat(stderrChunks).toString(),
-        });
         resolve(defaultScreenshot);
         return;
       }