Simpler way to ensure that externals points to the right URL

Build/AtlasBuildScripts/checkout_atlasexternals.sh

@@ -106,20 +106,11 @@ if [ ! -d "${SOURCEDIR}" ]; then
     _retry_ git clone ${EXTERNALSURL} ${SOURCEDIR}
 else
     echo "${SOURCEDIR} already exists -> assume previous checkout"
-fi
-
-# check whether the source directory points to the right repository
-RECLONE=false
-pushd ${SOURCEDIR}
-SOURCEURL=$(git remote get-url origin)
-if [ "${SOURCEURL}" != "${EXTERNALSURL}" ] ; then
-    echo "${SOURCEURL} wasn't cloned from ${EXTERNALSURL}, deleting"
-    RECLONE=true
-fi
-popd
-if [ $RECLONE = true ] ; then
-    rm -rf ${SOURCEDIR}
-    _retry_ git clone ${EXTERNALSURL} ${SOURCEDIR}
+    # make sure it points to the right place
+    (
+        cd ${SOURCEDIR}
+        git remote set-url origin ${EXTERNALSURL}
+    )
 fi
 
 # Get the appropriate version of it: