Fix runtest.py if Aegis is installed but it's not being run inside an active change.
Fix runtest.py if Aegis is installed but it's not being run inside an active change.

timj/scons,timj/scons,andrewyoung1991/scons,Distrotech/scons,andrewyoung1991/scons,timj/scons,andrewyoung1991/scons,timj/scons,timj/scons,andrewyoung1991/scons,andrewyoung1991/scons,Distrotech/scons,Distrotech/scons,timj/scons,Distrotech/scons,Distrotech/scons,timj/scons,andrewyoung1991/scons,timj/scons,andrewyoung1991/scons,timj/scons,andrewyoung1991/scons,andrewyoung1991/scons