Merge similar error strings.

props pavelevap.
fixes #32327.

git-svn-id: https://develop.svn.wordpress.org/trunk@32471 602fd350-edb4-49c9-b593-d223f7449a82

src/wp-includes/atomlib.php

@@ -130,7 +130,8 @@ class AtomParser {
             if($this->debug) $this->content .= $data;
 
             if(!xml_parse($parser, $data, feof($fp))) {
-                trigger_error(sprintf(__('XML error: %s at line %d')."\n",
+                /* translators: 1: error message, 2: line number */
+                trigger_error(sprintf(__('XML Error: %1$s at line %2$s')."\n",
                     xml_error_string(xml_get_error_code($parser)),
                     xml_get_current_line_number($parser)));
                 $ret = false;