Fix the parsing of the REST API XML response

The depth of some fields was not correct for the response obtained
through the REST API, which is the first one tried and the only one that
will survive in the future with VOMS-AA.

In addition, VOMS-AA returns a numeric code for an error condition, not
a string like VOMS server.

src/common/xmlcc.cc

@@ -491,7 +491,7 @@ static void endans(void *userdata, const char *name)
     a->num = atoi(a->value.c_str());
   }
   else if ((!strcmp(name, "message")) && 
-           (a->depth == 3)) {
+           (a->depth == 3 || a->depth == 2)) {
     a->message = a->value;
   }
   else if (!strcmp(name, "warning")) {
@@ -501,10 +501,10 @@ static void endans(void *userdata, const char *name)
     a->a->errs.push_back(e);
   }
   else if ((!strcmp(name, "code")) && 
-           (a->depth == 3)) {
+           (a->depth == 2)) {
     const char *msg = a->value.c_str();
 
-    if (!strcmp(msg, "NoSuchUser"))
+    if (!strcmp(msg, "NoSuchUser") || atoi(msg) == ERR_NOT_MEMBER)
       a->num = ERR_NOT_MEMBER;
     else if (!strcmp(msg, "SuspendedUser"))
       a->num = ERR_SUSPENDED;