contrib: disable building secp256k1 benchmarks

contrib/make_libsecp256k1.sh

@@ -49,6 +49,7 @@ info "Building $pkgname..."
             --enable-module-recovery \
             --enable-experimental \
             --enable-module-ecdh \
+            --disable-benchmark \
             --disable-tests \
             --disable-static \
             --enable-shared || fail "Could not configure $pkgname. Please make sure you have a C compiler installed and try again."