tests/run-multitests.py: Read IP address from boot nic if available.

This works if your network is pre-configured in boot.py as an object called
"nic".  Without this, multitests expects to access the WLAN/LAN class which
isn't always correct.
Signed-off-by: Andrew Leech <andrew@alelec.net>

tests/run-multitests.py

@@ -63,13 +63,16 @@ class multitest:
     @staticmethod
     def get_network_ip():
         try:
-            import network
-            if hasattr(network, "WLAN"):
-                ip = network.WLAN().ifconfig()[0]
-            else:
-                ip = network.LAN().ifconfig()[0]
+            ip = nic.ifconfig()[0]
         except:
-            ip = HOST_IP
+            try:
+                import network
+                if hasattr(network, "WLAN"):
+                    ip = network.WLAN().ifconfig()[0]
+                else:
+                    ip = network.LAN().ifconfig()[0]
+            except:
+                ip = HOST_IP
         return ip
 
 {}