Fixed issue in file capture directory that broke the scheduler

A recent change to capture.cpp renamed the file save location to fileDirectoryTectory from FITSDirectory. This looks like a replace gone wrong. It also broke the scheduler because it was looking for files in the wrong place.

This was discussed in this thread: https://indilib.org/forum/ekos/7788-scheduler-not-seeing-the-acquired-images.html

This commit reverts the name back to FITSDirectory in capture.cpp preserving backwards comparability and fixing the scheduler issue.