Make get_current_sdk_version more resilient

Author: rbanffy

resources/get_current_sdk_version.sh

@@ -1,8 +1,17 @@
 #!/bin/sh
 
-if [ -f /usr/bin/curl ]
+LAST_KNOWN_GOOD_VERSION="1.9.40"
+
+if [ -f $(which curl) ]
 then
-    curl -s https://storage.googleapis.com/appengine-sdks/featured/VERSION | grep release | awk -F '\"' '{print $2}'
+    VERSION=$(curl -s https://storage.googleapis.com/appengine-sdks/featured/VERSION | grep release | awk -F '\"' '{print $2}')
 else
-    wget -q -O - https://storage.googleapis.com/appengine-sdks/featured/VERSION | grep release | awk -F '\"' '{print $2}'
+    VERSION=$(wget -q -O - https://storage.googleapis.com/appengine-sdks/featured/VERSION | grep release | awk -F '\"' '{print $2}')
 fi
+
+if [ VERSION="0.0.0" ]
+then
+    VERSION=$LAST_KNOWN_GOOD_VERSION
+fi
+
+echo $VERSION