Remove problematic sniffer code resulting in no header found even when it exists

See nf-core/funcscan#227

Author: jfy133

nf_core/pipeline-template/bin/check_samplesheet.py

@@ -158,9 +158,6 @@ def sniff_format(handle):
     peek = read_head(handle)
     handle.seek(0)
     sniffer = csv.Sniffer()
-    if not sniffer.has_header(peek):
-        logger.critical("The given sample sheet does not appear to contain a header.")
-        sys.exit(1)
     dialect = sniffer.sniff(peek)
     return dialect