Remove duplicate switch cases for code clarity (#303)

If there are multiple switch cases, only the earliest one is used.

On line 444 of SQLProcessor, `case ';'` was a `continue 2;` instead.

Detected via static analysis

Author: TysonAndre

src/PHPSQLParser/processors/ExpressionListProcessor.php

@@ -274,7 +274,6 @@ public function process($tokens) {
                 case 'AND':
                 case '&&':
                 case 'BETWEEN':
-                case 'AND':
                 case 'BINARY':
                 case '&':
                 case '~':

src/PHPSQLParser/processors/SQLProcessor.php

@@ -494,7 +494,6 @@ public function process($tokens) {
 
             case '':
             case ',':
-            case ';':
                 break;
 
             default: