The -t, --targets option misses first record of new sequence

This command
```
echo -e "##fileformat=VCFv4.2\n##contig=<ID=1,length=248956422>\n##contig=<ID=2,length=248956422>\n#CHROM\tPOS\tID\tREF\tALT\tQUAL\tFILTER\tINFO\n1\t1\t.\tA\tC\t.\t.\t.\n2\t1\t.\tA\tC\t.\t.\t.\n2\t2\t.\tA\tC\t.\t.\t." | bcftools view -Ht 2
```
outputs
```
2	2	.	A	C	.	.	.
```
but should output
```
2	1	.	A	C	.	.	.
2	2	.	A	C	.	.	.
```