Format of the initialization string does not conform to to specification starting at index 0

This usually means your connection string isn't any good. If you look at the stack trace, you'll notice that this is failing when trying to interpret your connection string.

Check your connection string to make sure it is correct - or post it here for help (but without any sensitive information such as passwords ;) )

UPDATE

According to the SqlDatabase documentation the SqlDatabase class takes a connection string, not a key to the connection string configuration.

So

new SqlDatabase("SiteSqlServer");

Should be

var connection = ConfigurationManager.ConnectionStrings["SiteSqlServer"];

Database objDB = new SqlDatabase(connection.ConnectionString);

(I have omitted any defensive code here for brevity)