Update //components/OWNERS to properly allow trivial changes

Followup to
https://chromium-review.googlesource.com/c/chromium/src/+/1470974 to
realize the intent of that CL.

Credit to thakis@, who noticed the error.

Change-Id: Ia0c8d02603713097566e8788e0e36083acbffeec
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1575498Reviewed-by: Nico Weber <thakis@chromium.org>
Commit-Queue: Nico Weber <thakis@chromium.org>
Cr-Commit-Position: refs/heads/master@{#652511}

components/OWNERS

@@ -38,4 +38,4 @@ per-file *.xtb=file://tools/translation/TRANSLATION_OWNERS
 # This is for the common case of adding or removing tests or files. If you're
 # making structural changes, please get a review from one of the overall
 # components OWNERS.
-per-file BUILD.gn=file://build/OWNERS
+per-file BUILD.gn=*