On my car, ans presumably yours too (better check it first though) there are 4 wires going to the relay marked as follows
C1 - White with a brown tracer which goes to the Starter Motor. This activates the large relay on the starter and spins the motor when live.
C2 - Brown wire which comes from the shunt, so is live all of the time
W1 - comes from the ignition switch and is only live when the ignition is turned round to start position. This is the wire you have joined together.
W2 - earth
So, when the ignition is turned a current is sent to the inhibitor switch. If this switch is on (or you have joined them together), it carries onto the relay and through the relay to earth. Current passing through the relay from W1 to W2 operates a switch which connects C1 to C2. If this switch is jammed on, then the starter motor circuit will be live all of the time and spin the starter.
Pull off C1 to stop the starter spinning.
With the ignition off, see if the wire to W1 is live. It shouldn't be. If it is live, you have a problem with your ignition switch or somewhere in the ignition system.
Then see if C1 is live - again it shouldn't be. If W1 is lot live, but c1 is, then the relay is jammed on. Get a new one.
Hope this helps
Richard