VMM/Config: removed the default value of misc.dovecot_version.
There are too many different versions installed on different systems.
So, it doesn't make much sense to have a default value.
668951708f2f28f49da94479a89c40ab8c8a9b01 trunk
668951708f2f28f49da94479a89c40ab8c8a9b01 vmm-0.4
9b39f828aa8a7661582859ec75e1423c38dbbef2 vmm-0.3.1
bb0aa2102206cd25a99e64d0b94bcd6c2018d3df vmm-0.3
bc41dfcef0ad915ccca987b1b381d8c68ab70f2f vmm-0.5
dc98cc162c66d8a5227b6e7c5e7215757159688c vmm-0.5.1
3e972996da7f135f0a91afaea831befbac4c3351 vmm-0.5.2
668951708f2f28f49da94479a89c40ab8c8a9b01 trunk
0000000000000000000000000000000000000000 trunk