Register VCFAltHeaderLine

Author: tomwhite

src/main/java/org/disq_bio/disq/serializer/DisqKryoRegistrator.java

@@ -125,6 +125,7 @@ public void registerClasses(final Kryo kryo) {
     kryo.register(htsjdk.variant.variantcontext.VariantContext.Type.class);
 
     // htsjdk.variant.vcf
+    kryo.register(htsjdk.variant.vcf.VCFAltHeaderLine.class);
     kryo.register(htsjdk.variant.vcf.VCFCompoundHeaderLine.SupportedHeaderLineType.class);
     kryo.register(htsjdk.variant.vcf.VCFContigHeaderLine.class);
     kryo.register(htsjdk.variant.vcf.VCFFilterHeaderLine.class);