bump libsecp256k1 version

contrib/make_libsecp256k1.sh

@@ -10,7 +10,7 @@
 # Or for a Windows x86_64 (64-bit) target, run:
 # $ GCC_TRIPLET_HOST="x86_64-w64-mingw32" ./contrib/make_libsecp256k1.sh
 
-LIBSECP_VERSION="b408c6a8b287003d1ade5709e6f7bc3c7f1d5be7"
+LIBSECP_VERSION="dbd41db16a0e91b2566820898a3ab2d7dad4fe00"
 
 set -e
 
@@ -29,6 +29,10 @@ info "Building $pkgname..."
         git clone https://github.com/bitcoin-core/secp256k1.git
     fi
     cd secp256k1
+    if ! $(git cat-file -e ${LIBSECP_VERSION}) ; then
+        info "Could not find requested version $LIBSECP_VERSION in local clone; fetching..."
+        git fetch --all
+    fi
     git reset --hard
     git clean -f -x -q
     git checkout $LIBSECP_VERSION