Update index.js

Updated the code, for issue OmniSharp#1

//from
else {
    module.exports = require(path.join(__dirname, 'dist/index'));
}

//to 
else {
    module.exports = require(path.join(__dirname, 'dist/src/index'));
}

index.js

@@ -4,5 +4,5 @@ var fs = require('fs'), path = require('path');
 if (fs.existsSync(path.resolve(__dirname, 'src/index.js'))) {
     module.exports = require(path.join(__dirname, 'src/index'));
 } else {
-    module.exports = require(path.join(__dirname, 'dist/index'));
+    module.exports = require(path.join(__dirname, 'dist/src/index'));
 }