Update bc submodule

DaveRandom · nikic · commit 56678599a004 · 2018-08-19T12:37:17.000+09:00
diff --git a/bc b/bc
@@ -1 +1 @@
-Subproject commit aeae4678cc24d73f020957880967c02011e44d9a
+Subproject commit fa341eba48006cf46486d74e99620bd1ce685983
