merge db-setup-pg-shmmax [r=andreas] [trivial]
merge db-setup-pg-shmmax [r=andreas] [trivial]

On pg9.1 and certain memory configurations, the settings introduced by
dev/db-setup can overrun the default shmmax settings on the kernel. This change
catches the error and attempts to tune the kernel correctly

PyMamba/mamba-storm,PyMamba/mamba-storm,PyMamba/mamba-storm