#15 list-open-calls double-counts calls if there are multiple telescopes for the same solicitation/call

$ prop --list-open-calls
2 pending calls found.

VLBA 26A (NRAO) - 3 CoI proposals pending.
VLA 26A (NRAO) - 3 CoI proposals pending.

For example: ``` $ prop --list-open-calls 2 pending calls found. VLBA 26A (NRAO) - 3 CoI proposals pending. VLA 26A (NRAO) - 3 CoI proposals pending. ```