Bug 15697: Unnecessary comma between title and subtitle on opac-detail.pl

Bug 15697: Unnecessary comma between title and subtitle on opac-detail.pl

To test:
1 - Go to Administration->Keyword to MARC mapping
2 - Add a mapping (or ensure it exists)
    Field name: subtitle
    MARC field: 245
    MARC subfield: b
3 - View a record with a subtitle in the opac
4 - Note in MARC 21 you have "Title of record:, subtitle of record"
5 - Apply patch
6 - View the record again and note the comma is no longer present.

Note: this patch removes the comma only for MARC21 where subtitle is not
repeatable. UNIMARC seems to be repeatable and does not include
punctuation so I believe this may be needed there.

Signed-off-by: Hector Castro <hector.hecaxmmx@gmail.com>
Works as described. Comma removed from title of the window and breadcrumb
section

Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Kyle M Hall <kyle@bywatersolutions.com>
(cherry picked from commit e19db8ca32dd776263b73474ece4e17d88ab17b4)
Signed-off-by: Julian Maurice <julian.maurice@biblibre.com>