Meshtastic Protobufs v2.1.21

What's Changed

• Removing Portnum we didn't actually use by @thebentern in #367
• Added Nano G2 Ultra to 18 by @neilhao in #370
• Fix unmappable character (0x98) for encoding windows-1251 #373 by @ComBatVision in #374

New Contributors

• @ComBatVision made their first contribution in #374

Full Changelog: v2.1.20...v2.1.21