Change the default pre shared key to break backward compatibility of default channel

src/mesh/Channels.cpp

@@ -7,7 +7,7 @@
 
 /// 16 bytes of random PSK for our _public_ default channel that all devices power up on (AES128)
 static const uint8_t defaultpsk[] = {0xd4, 0xf1, 0xbb, 0x3a, 0x20, 0x29, 0x07, 0x59,
-                                     0xf0, 0xbc, 0xff, 0xab, 0xcf, 0x4e, 0x69, 0xbf};
+                                     0xf0, 0xbc, 0xff, 0xab, 0xcf, 0x4e, 0x69, 0x01};
 
 Channels channels;