Fix bug not getting convert factor for question channel

closes #152 (closed), #151 (closed), #149 (closed)

For channel that end with question mark '?' in DB, the '?' represent for a number in real channel. Ex: VM1, VM2 in DB is VM?

This MR fix the bug that not able to get the correct conversion factor for that kind of channels.

This also correct conversion factor for Centaur in DB from 0.001 to 0.000001:

UPDATE Channels SET convertFactor=0.000001 WHERE dataType='Centaur' AND channel='VM?'

documentation/40 _ Firmware Notice.help.md

+Pegasus firmware was updated to record VEI in millivolts. 
+Previous versions of the firmware recorded VEI in microvolts.
+
+We decided to apply VEI's conversion factor in newer version of Pegasus. 
+If user may see higher than expected values in the older version of Pegasus.
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