Bump Sources/secp256k1/secp256k1 from 979961c to 670cdd3 (#12)

dependabot[bot] · web-flow · commit 2236e4aa3ad6 · 2020-08-17T05:52:50.000Z
diff --git a/Sources/secp256k1/secp256k1 b/Sources/secp256k1/secp256k1
@@ -1 +1 @@
-Subproject commit 979961c506c423034a35e62c5937c837bc179358
+Subproject commit 670cdd3f8be25f81472b2d16dcd228b0d24a5c45
