[iso19139] comment before md-identification ends up as being selected

[pvgenuchten]

no SV_ServiceIdentification or md_metadataidentification element is selected if the element is prepended with a comment

  <gmd:identificationInfo>
    <!-- ## any comment here, fails the xml parsing, because the first element is taken, which is the comment ## -->
    <srv:SV_ServiceIdentification uuid="a65c20b3-9f94-3bad-a307-a61021331d8c">

[tomkralidis]

FYI can be reproduced with:

import sys

from owslib.etree import etree
from owslib.iso import MD_Metadata

m = MD_Metadata(etree.parse(sys.argv[1]))
print(m.identification)