move special hack for US states to legacy tokenizer

The hack for IL, AL and LA is only needed because these abbreviations
are removed by the legacy tokenizer as a stop word. There is no need
to keep the hack for future tokenizers. Move it therefore to the
token extraction function.

lib-php/Phrase.php

@@ -9,7 +9,8 @@ namespace Nominatim;
  */
 class Phrase
 {
-    // Complete phrase as a string.
+    // Complete phrase as a string (guaranteed to have no leading or trailing
+    // spaces).
     private $sPhrase;
     // Element type for structured searches.
     private $sPhraseType;