[ios] Fix Translate Modal Change Language Crash

When attempting to get the source languages to switch to,
a crash can occur if the self.newSourceLanguageIndex is -1.
In this line of code, it should be self.newTargetLanguageIndex

Bug: 1113818
Change-Id: I4260bc32ba620927a60a966ee8b67c4b1586bc02
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2341388
Commit-Queue: Chris Lu <thegreenfrog@chromium.org>
Commit-Queue: Sergio Collazos <sczs@chromium.org>
Auto-Submit: Chris Lu <thegreenfrog@chromium.org>
Reviewed-by: Sergio Collazos <sczs@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#795576}
Cr-Mirrored-From: https://chromium.googlesource.com/chromium/src
Cr-Mirrored-Commit: 49e532f156acb9091cb0a9fe6bcc5570fef4541e
1 file changed