refactor server_url method
refactor server_url method

IsmailM/sequenceserver,lepbase/lepbase-sequenceserver,lepbase/lepbase-sequenceserver,aldermossy/sequenceserver,deepakunni3/sequenceserver,yeban/sequenceserver,yeban/sequenceserver,vivekiitkgp/sequenceserver,elsiklab/sequenceserver,jasminZ/sequenceserver,elsiklab/sequenceserver,IsmailM/sequenceserver,aldermossy/sequenceserver,jasminZ/sequenceserver,jasminZ/sequenceserver,aldermossy/sequenceserver,aldermossy/sequenceserver,elsiklab/sequenceserver,yeban/sequenceserver,yeban/sequenceserver,IsmailM/sequenceserver,lepbase/lepbase-sequenceserver,vivekiitkgp/sequenceserver,deepakunni3/sequenceserver,deepakunni3/sequenceserver,vivekiitkgp/sequenceserver