Move SdFat to master/head (#422)

earlephilhower · web-flow · commit d5ddf4cd7f24 · 2022-01-19T12:30:12.000-08:00
SdFat used to point to unnamed commit in the ESP8266SdFat repo.
Master in that repo has now been moved to that commit, so make this
core use the master branch for sanity's sake.
diff --git a/libraries/SdFat b/libraries/SdFat
@@ -1 +1 @@
-Subproject commit 3a6b688b1b5112d149295813660ef9b2b7cc0ee5
+Subproject commit 43a65b42d5a827092188cfe11fb27237da252692
