Some URLs in 500 notes do not resolve

[jenniferward]

Some URLs in 500 notes in Sources do not resolve.
<a> is added at the end of the URL. Some systems seem to be able to deal with it, but others lead to broken links.

(URLs in 500 notes aren't ideal, but people put them there.)

Examples:
https://muscat.rism.info/admin/sources/458001401
=500 ##$aOriginal catalog entry: http://rsqv.de/q00015
If you click on it, the URL is: https://rsqv.de/q00015/a> (or mouseover )

https://muscat.rism.info/admin/sources/1001190376
=500 ##$aDating according to: Dated Plate Numbers for André Verlag http://www.dfenton.com/pn2.html$801
URL goes to http://www.dfenton.com/pn2.html%3C/a%3E which results in a 404 error.

https://muscat.rism.info/admin/sources/1001241203
=500 ##$aCfr. Clori - Archivio della cantata italiana, n. 321 (http://www.cantataitaliana.it/query_bid.php?id=321)
The ) is additionally taken as part of the URL and resolves as http://www.cantataitaliana.it/query_bid.php?id=321%3C/a%3E)

Exceptions:
https://muscat.rism.info/admin/sources/1001274152
=500 ##$aDas Stück erschien in Teil 1 der Druckausgabe. Link zum Digitalisat der gedruckten Ausgabe von Schott, D-Mbs, Mus.Schott.Ha 12287-3: http://mdz-nbn-resolving.de/urn:nbn:de:bvb:12-bsb00149033-3
This record adds <a> to the URL but the intended page is displayed.