allow postgresql connection without password

I am trying to run a thesis project on my local environment. In order to achieve this, i installed postgresql (v9.2) and have to connect it with my computer's user name and no password! (it is not possible to change the code in jar file and the configuration file is missing!) To accomplish this:
- i added a login role (by using pgAdmin GUI) with my computer's name and defined it with no password
- i edited pg_hba.conf file as follows:

host    all     all    127.0.0.1/32  md5trust