NethVoice: add Terrecablate and VoiPTel VoIP provider into wizard menu

[andrea-marchionni]

Added the following providers to the NethVoice menu:

• Terrecablate
• VoiPTel (new SIP server compared to the existing one)

[Amygos]

Testing release nethesis/ns8-nethvoice 1.1.4-testing.8