bug report with "mass_offsets" and "prec_NL_ions" parameters

[Jimmy Eng]

The "mass_offsets" parameter was introduced in Comet version 2015.02.0 and the "precursor_NL_ions" parameter was introduced in Comet version 2019.01.0.

Since version 2017.01.0 for "mass_offsets" and version 2019.01.0 for "precursor_NL_ions", the vectors storing these parameter values were incorrectly being cleared after searching the first input file.  So if one instance of Comet was invoked with multiple input files, only the first file would be correctly analyzed with these parameters.  This will be addressed in the next release.