Bug#844879: swift-im must build-depend on zlib1g-dev

[Adrian Bunk]

Control: retitle -1 swift-im must build-depend on zlib1g-dev

This is likely fallout from the change that libssl-dev no longer 
depending on zlib1g-dev, exposing missing (build)dependencies on
zlib1g-dev elsewhere.

cu
Adrian

-- 

       "Is there not promise of rain?" Ling Tan asked suddenly out
        of the darkness. There had been need of rain for many days.
       "Only a promise," Lao Er said.
                                       Pearl S. Buck - Dragon Seed