python-managesieve: Add --port option to sieveshell for overriding the default port

This update fixes the following issue for python-managesieve:
- bnc#811230: Add --port option to sieveshell for overriding the default port, previously it was hardcoded to port 2000

Fixed bugs
bnc#811230
sieveshell from python-managesieve hardcodes port 2000
Selected Binaries
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