KSambashare: handle "Weak crypto is allowed" error message

Testparm output has changed, it now outputs for instance:

$ testparm -d0 -s --parameter-name="usershare path"
Load smb config files from /etc/samba/smb.conf
Loaded services file OK.
Weak crypto is allowed

WARNING: The 'netbios name' is too long (max. 15 chars).

/var/lib/samba/usershares

Take into account this added "Weak crypto is allowed" line and take into account the added space.

This allows to have the debug message:

kf.kio.core: Your samba 'netbios name' parameter was longer than the authorized 15 characters.
 It may be because your hostname is longer than 13 and samba default 'netbios name' defaults to 'hostname-W', here: "meven-XPS-13-9370-W" 
 If that it is the case simply define a 'netbios name' parameter in /etc/samba/smb.conf at most 15 characters long

Instead of

kf.kio.core: We got some errors while running testparm "Weak crypto is allowed\n\nWARNING: The 'netbios name' is too long (max. 15 chars)."