Fix empty literal string becomes non-empty-string

when max literal string length is 0, which means literal strings are disabled

src/Psalm/Type.php

@@ -287,7 +287,7 @@ public static function getAtomicStringFromLiteral(string $value, bool $from_docb
         $type = $config->eventDispatcher->dispatchStringInterpreter($event);
 
         if (!$type) {
-            if (strlen($value) < $config->max_string_length) {
+            if ($value === '' || strlen($value) < $config->max_string_length) {
                 $type = new TLiteralString($value, $from_docblock);
             } else {
                 $type = new TNonEmptyString($from_docblock);