* fix for RAK terminal chat

platformio.ini

@@ -96,7 +96,7 @@ extends = Heltec_lora32_v3
 build_flags =
   ${Heltec_lora32_v3.build_flags} 
   -D MAX_CONTACTS=100
-  -D MAX_CHANNELS=1
+  -D MAX_GROUP_CHANNELS=1
 ;  -D MESH_PACKET_LOGGING=1
 ;  -D MESH_DEBUG=1
 build_src_filter = ${Heltec_lora32_v3.build_src_filter} +<../examples/simple_secure_chat/main.cpp>
@@ -263,7 +263,7 @@ extends = rak4631
 build_flags =
   ${rak4631.build_flags} 
   -D MAX_CONTACTS=100
-  -D MAX_CHANNELS=1
+  -D MAX_GROUP_CHANNELS=1
   -D MESH_PACKET_LOGGING=1
   -D MESH_DEBUG=1
 build_src_filter = ${rak4631.build_src_filter} +<../examples/simple_secure_chat/main.cpp>