Avoid yield() while in SYS context

earlephilhower · earlephilhower · commit 288446e669d9 · 2020-12-19T12:54:25.000-08:00
diff --git a/libraries/ESP8266SdFat b/libraries/ESP8266SdFat
@@ -1 +1 @@
-Subproject commit c91f12a708eef896abf74f7eae767194d4440740
+Subproject commit 81aa7e68681a6061e95cde2c248c102e51c7a96c
