* server-src/driver.c: Degraded dles onlt for degraded storage.
* server-src/driverio.c: Set default degraded_mode.
* server-src/driverio.h (taper_t): Add degraded_mode.


git-svn-id: https://svn.code.sf.net/p/amanda/code/amanda/trunk@5314 a8d146d6-cc15-0410-8900-af154a0219e0