Re-add getAddress() for non-MuxRPC method calls

Problem: Removing all `getAddress()` usage was too aggressive -- it's
still a method that Secret-Stack exposes, and so we should still test
for it, but we should **only test for it over in-process method calls**.
When using MuxRPC, we should always use `address()`.

Solution: Use `getAddress()` when the method isn't being called via
MuxRPC.

test/caps.js

···
   temp: 'server-bob',
   port: 45452, timeout: 1400,
   keys: ssbKeys.generate(),
-  seeds: [dbA.address()],
+  seeds: [dbA.getAddress()],
   level: 'info'
 })
 
···
 })
 
 tape('cannot connect if different shs caps, custom -> default', function (t) {
-  dbA.connect(dbB.address(), function (err) {
+  dbA.connect(dbB.getAddress(), function (err) {
     t.ok(err)
     console.log(err.stack)
 
···
 })
 
 tape('cannot connect if different shs caps, default -> custom', function (t) {
-  dbB.connect(dbA.address(), function (err) {
+  dbB.connect(dbA.getAddress(), function (err) {
     t.ok(err)
 
     console.log(err.stack)
···
 })
 
 tape('cannot connect if different shs caps, default -> custom', function (t) {
-  dbC.connect(dbA.address(), function (err) {
+  dbC.connect(dbA.getAddress(), function (err) {
     if(err) throw err
     t.end()
   })