* src/augeas.c (init_root): when root0 == "", use "/" as root
* src/augeas.c (init_root): when root0 == "", use "/" as root

When an empty string is passed as root0, make sure we do not make an
invalid memory access when we look for the trailing slash.

Reported and fix suggested by Jeff Johnson <n3npq@mac.com>

hercules-team/augeas-do-not-use,jtopjian/augeas,dafugg/augeas,domcleal/augeas,domcleal/augeas,bkearney/augeas,domcleal/augeas,GeoffWilliams/augeas,pevalme/augeas,ptoscano/augeas,jasperla/augeas,dafugg/augeas,bkearney/augeas,lutter/augeas,kunkku/augeas,dafugg/augeas,mlichvar/augeas,ptoscano/augeas,ptoscano/augeas,jjlin/augeas,mchf/augeas,lutter/augeas,bkearney/augeas,kumy/augeas,jasperla/augeas,hercules-team/augeas,MikaelSmith/augeas,kunkku/augeas,kunkku/augeas,hercules-team/augeas-do-not-use,pevalme/augeas,GeoffWilliams/augeas,hercules-team/augeas,bkearney/augeas,MikaelSmith/augeas,lutter/augeas,jjlin/augeas,jjlin/augeas,manandbytes/augeas,kumy/augeas,hercules-team/augeas-do-not-use,raphink/augeas,raphink/augeas,mlichvar/augeas,manandbytes/augeas,mlichvar/augeas,pevalme/augeas,jtopjian/augeas,kumy/augeas,kumy/augeas,mchf/augeas