Use of String#substring instead of String#slice

Benchmarks show that using substring is faster than slice

lib/dialects/postgres/range.js

@@ -34,7 +34,7 @@ module.exports = {
     AttributeType = AttributeType || ''; // if attribute is not defined, assign empty string in order to prevent
     AttributeType = AttributeType || ''; // if attribute is not defined, assign empty string in order to prevent
                                          // AttributeType.toString() to fail with uncaught exception later in the code
                                          // AttributeType.toString() to fail with uncaught exception later in the code
     var result = value
     var result = value
-      .slice(1, -1)
+      .substring(1, value.length - 1)
       .split(',', 2);
       .split(',', 2);
 
 
     if (result.length !== 2) return value;
     if (result.length !== 2) return value;