Incorrect use of SNCA if signal files are in OpenRails subdirectory

[r.roeterdink]

If the signal definition files (sigcfg.dat and related script files) are placed in OpenRails subdirectory, the value for SignalNumberClearAhead as defined per signal type should aways be interpreted as SIGNALS to count, and not SIGNALHEADS, regardless of the number of lines defining the SNCA value.

[r.roeterdink (r-roeterdink)]

Fix committed in 3287.