update mbed bridge submodule

Wenn0101 · Wenn0101 · commit 1fe1cac39817 · 2021-03-16T12:44:39.000-06:00
diff --git a/cores/arduino/mbed-bridge b/cores/arduino/mbed-bridge
@@ -1 +1 @@
-Subproject commit 56045b545168284ad6e45f7112493646b6b9ecfb
+Subproject commit 63a8d6b3d8f57999b7af867ceb93a6f7367ca12a
