DNS Import fail with TXT resource records

DNS Import fail to handle TXT resource records. This issue is related with #3792 (closed)

If the record's data has a semicolon or some uppercase letters, the import fail to load the correct values.

For example, if the RR is a DomainKey record (Or DKIM), it has multiple values separated with semicolons and the case of the key must be keeped.

myselector._domainkey 3600  TXT "k=rsa; t=y; p=MHwwDQYJKoZIhvcNAQEBBQADawAwaAJhALsL5WZEX2crTmZN+WeuloQuRVzEsa5MZve4SC6j4pMtfBM/yqrFTuEZN2TLrc0AMFzwEGxoAA5XF4vhxzxvSLzw/wZNk/QmK6OLAyw8c0qw6Ke5R8dmVj3gI7T98cEfgQIDAQAB"

After importing the zone's file, the new registry is:

myselector._domainkey 3600  TXT "k=rsa"

This resource records must be left as they are, without truncate them on the semicolon and without change their case.