Handle PEDIGREE header lines differently for vcf4.2 vs vcf4.3.

[cmnbroad]

Fix https://github.com/samtools/htsjdk/issues/1400.

[codecov-io]

Codecov Report

Merging #1401 into master will decrease coverage by 0.009%. The diff coverage is 100%.

@@               Coverage Diff               @@
##              master     #1401       +/-   ##
===============================================
- Coverage     68.049%   68.041%   -0.009%     
  Complexity      8372      8372               
===============================================
  Files            573       573               
  Lines          33893     33893               
  Branches        5663      5663               
===============================================
- Hits           23064     23061        -3     
- Misses          8641      8643        +2     
- Partials        2188      2189        +1

Impacted Files	Coverage Δ	Complexity Δ
...main/java/htsjdk/variant/vcf/AbstractVCFCodec.java	76.218% <100%> (ø)	101 <0> (+1)	:arrow_up:
...samtools/util/AsyncBlockCompressedInputStream.java	72% <0%> (-4%)	12% <0%> (-1%)

[lbergelson]

Fixes #1400