cdr_pgsql does not detect when a table is found.

This change adds an ERROR message to let you know when a failure exists to
get the columns from the pgsql database, which typically means that the
table does not exist.

(closes issue #17478)
Reported by: kobaz
Patches:
      cdr_pgsql.patch uploaded by kobaz (license 834)
Tested by: kobaz, russell, lmadsen

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@275626 65c4cc65-6c06-0410-ace0-fbb531ad65f3

cdr/cdr_pgsql.c

@@ -526,6 +526,13 @@ static int config_module(int reload)
 		}
 
 		rows = PQntuples(result);
+		if (rows == 0) {
+			ast_log(LOG_ERROR, "cdr_pgsql: Failed to query database columns. No columns found, does the table exist?\n");
+			PQclear(result);
+			unload_module();
+			return AST_MODULE_LOAD_DECLINE;
+		}
+
 		for (i = 0; i < rows; i++) {
 			fname = PQgetvalue(result, i, 0);
 			ftype = PQgetvalue(result, i, 1);