Update shairport-sync.spec

Update shairport-sync.spec

- Fixed Version: from 2.8.2 to 2.8.3.
- Fixed Release: special characters were reported as non-compliant by checkinstall
- Replaced all occurrences of character Horizontal Tab, ASCII Dec #9, that was used everywhere between a colon and tag value, with a Blank Space ASCII Dec #32. Horizontal Tab caused problems when creating a .deb package, tag values were reported as non-compliant by checkinstall.
- Fixed Requires: popt

If a .deb package was created with Requires: popt, the .deb package could not be installed due to a missing Package popt:

venca@cubox-i:~/shairport-sync$ sudo dpkg -i shairport-sync_2.8.3-1_armhf.deb
Selecting previously unselected package shairport-sync.
(Reading database ... 52746 files and directories currently installed.)
Preparing to unpack shairport-sync_2.8.3-1_armhf.deb ...
Unpacking shairport-sync (2.8.3-1) ...
dpkg: dependency problems prevent configuration of shairport-sync:
 shairport-sync depends on popt; however:
  Package popt is not installed.

dpkg: error processing package shairport-sync (--install):
 dependency problems - leaving unconfigured
Processing triggers for man-db (2.7.0.2-5) ...
Errors were encountered while processing:
 shairport-sync

After Requires: popt was changed to Requires: libpopt-dev and a new .deb package was created, the new .deb package could be installed.