[roll] Roll fuchsia [rust] fix clippy::uninlined_format_args in mock-omaha-server

Rust toolchain rolls are blocked because the new version of clippy
complains about this lint. This commit fixes that.

Original-Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1263490
Original-Revision: e6750b39a050a530ecc2f04ca5076a07aec1bbaf
GitOrigin-RevId: d7d64783ea5fb6457ae2b2fd38fdd509123b560b
Change-Id: I55d148fe4fd880110e340da54ab8cfdedc7919c4
diff --git a/stem b/stem
index 0715514..7a6c986 100644
--- a/stem
+++ b/stem
@@ -8,7 +8,7 @@
              root=""
              remote="https://fuchsia.googlesource.com/fuchsia"
              gerrithost="https://fuchsia-review.googlesource.com"
-             revision="2a4e51e201ec344d4955e8dd73d953da6d290e38"
+             revision="e6750b39a050a530ecc2f04ca5076a07aec1bbaf"
              />
   </imports>
 </manifest>