Update usddeck.c

[roeeSch]

Support config.txt files with lines which are pure comments such as the first line here:

# Config Vesion 1.2.3
100   # frequency
3    # buffer size
...
gyro.x
gyro.y
gyro.z
acc.x

[knmcguire]

Ah great, thanks!

This will fix issue #915? I wanted to look at this for a triage meeting but perhaps not necessary anymore!

We are in the middle or a release so we might wait a bit with merging this, but in the mean time @tobbeanton could take a look at it!

[roeeSch]

@knmcguire, I think this will fix #915.
I verified this functionality by updating the firmware and adding a comment to config.txt and checking the logs on the SD.

[krichardsson]

Merged
Thanks!

[krichardsson]

Fixes #915