fix sha256 fingerprint generation of downloaded golang archive

build_core.sh

@@ -38,7 +38,7 @@ else
     if [[ "$OSTYPE" == "linux-gnu"* ]]; then
       ACTUAL_FP=`sha256sum $GO_VERSION.tar.gz | cut -d " " -f1`
     else
-      ACTUAL_FP=`shasum -a 512256 $GO_VERSION.tar.gz | cut -d " " -f1`
+      ACTUAL_FP=`shasum -a 256 $GO_VERSION.tar.gz | cut -d " " -f1`
     fi
 
     if [[ ! $ACTUAL_FP == $EXPECTED_FP ]]