"No interface" better error message

It's not obvious how to fix it when you read the error message. It's way more obvious when you read the code.

This patch gives more clues to the user to fix it. Solves #1312 (closed)

app/modules/bma/index.ts

@@ -165,7 +165,7 @@ export const BmaDependency = {
         // Configuration errors
         if (!conf.nobma) {
           if(!conf.ipv4 && !conf.ipv6){
-            throw new Error("BMA: no interface to listen to.");
+            throw new Error("BMA: no interface to listen to. Provide ipv4/ipv6 interface or deactivate BMA");
           }
           if(!conf.remoteipv4 && !conf.remoteipv6 && !conf.remotehost){
             throw new Error('BMA: no interface for remote contact.');