Check return status of curl and report error

This is really handy if you run without DEBUG mode and curl has a problem (like out of date SSL certs)

acme.sh

@@ -491,8 +491,14 @@ _post() {
     CURL="$CURL --dump-header $HTTP_HEADER "
     if [ "$needbase64" ] ; then
       response="$($CURL -A "User-Agent: $USER_AGENT" -X POST --data "$body" $url | _base64)"
+      if [[ $? -gt 0 ]] ;then
+         _err "Curl failed with exit code $?, trying running script in DEBUG=1 mode"
+      fi
     else
       response="$($CURL -A "User-Agent: $USER_AGENT" -X POST --data "$body" $url)"
+      if [[ $? -gt 0 ]] ;then
+         _err "Curl failed with exit code $?, trying running script in DEBUG=1 mode"
+      fi
     fi
   else
     if [ "$needbase64" ] ; then
@@ -514,8 +520,14 @@ _get() {
   if _exists "curl" ; then
     if [ "$onlyheader" ] ; then
       $CURL -I -A "User-Agent: $USER_AGENT" $url
+      if [[ $? -gt 0 ]] ;then
+       _err "Curl failed with exit code $?, trying running script in DEBUG=1 mode"
+      fi
     else
       $CURL -A "User-Agent: $USER_AGENT" $url
+      if [[ $? -gt 0 ]] ;then
+       _err "Curl failed with exit code $?, trying running script in DEBUG=1 mode"
+      fi
     fi
   else
     _debug "WGET" "$WGET"