Bug 1893291: Adjusting the client_connections_intitution table

Removing the unsigned type so will match other 'id' columns and allow
foreign key connection to work on mysql 8

Change-Id: Iac2d8e0b23ff6d7f0d464b1d0b9217d19ccc7a1c
Signed-off-by: Robert Lyon <robertl@catalyst.net.nz>