Make query caching case insensitive, a=chris

diff --git a/src/models/PhraseModel.php b/src/models/PhraseModel.php
index 8be310a1f..04b4342b2 100755
--- a/src/models/PhraseModel.php
+++ b/src/models/PhraseModel.php
@@ -321,7 +321,8 @@ class PhraseModel extends ParallelModel
             $cache_results = false;
             if (C\nsdefined('USE_CACHE') && C\USE_CACHE &&
                 $save_timestamp == "" && $use_cache_if_allowed && !$network) {
-                $cache_results = self::$cache->get($phrase . $this->index_name);
+                $cache_results = self::$cache->get(mb_strtolower($phrase) .
+                    $this->index_name);
                 if (C\QUERY_STATISTICS) {
                     $this->query_info['QUERY'] .=
                         "$in2<b>Parse done by Cache Lookup</b><br />";
@@ -363,8 +364,8 @@ class PhraseModel extends ParallelModel
                     }
                     if (C\nsdefined('USE_CACHE') && C\USE_CACHE &&
                         $save_timestamp == "") {
-                        self::$cache->set($phrase.$this->index_name,
-                            [$word_structs, $format_words]);
+                        self::$cache->set(mb_strtolower($phrase) .
+                            $this->index_name, [$word_structs, $format_words]);
                     }
                 }
             }