Added initialization check to RADIUS ipv6 address

This prevents the border router from printing unnecessary error trace
when RADIUS is not enabled.

Author: Mika Leppänen

features/nanostack/mbed-mesh-api/mbed-mesh-api/WisunBorderRouter.h

@@ -331,6 +331,7 @@ class WisunBorderRouter {
     char *_shared_secret = NULL;
     uint16_t _shared_secret_len = 0;
     int8_t _mesh_if_id = -1;
+    bool _radius_ipv6_addr_init = false;
     bool _radius_ipv6_addr_set = false;
     bool _configured = false;
     bool _radius_timing_set = false;

features/nanostack/mbed-mesh-api/source/WisunBorderRouter.cpp

@@ -109,7 +109,7 @@ void WisunBorderRouter::stop()
 
 mesh_error_t WisunBorderRouter::configure()
 {
-#if defined(MBED_CONF_MBED_MESH_API_RADIUS_SHARED_SECRET) || defined(MBED_CONF_MBED_MESH_API_RADIUS_SERVER_IPV6_ADDRESS) || defined(MBED_CONF_MBED_MESH_API_RADIUS_RETRY_IMIN)
+#if defined(MBED_CONF_MBED_MESH_API_RADIUS_SHARED_SECRET) || defined(MBED_CONF_MBED_MESH_API_RADIUS_SERVER_IPV6_ADDRESS)
     mesh_error_t status;
 #endif
 
@@ -281,8 +281,10 @@ mesh_error_t WisunBorderRouter::set_radius_server_ipv6_address(const char *addre
         }
         // Stored address (returned by get) is in the format given by user of the interface
         strcpy(_radius_ipv6_addr, address);
+        _radius_ipv6_addr_init = true;
         _radius_ipv6_addr_set = true;
     } else {
+        _radius_ipv6_addr_init = true;
         _radius_ipv6_addr_set = false;
     }
 
@@ -303,6 +305,10 @@ mesh_error_t WisunBorderRouter::set_bbr_radius_address(void)
 {
     int status;
 
+    if (!_radius_ipv6_addr_init) {
+        return MESH_ERROR_NONE;
+    }
+
     if (_radius_ipv6_addr_set) {
         uint8_t ipv6_addr[16];
         if (!stoip6(_radius_ipv6_addr, strlen(_radius_ipv6_addr), ipv6_addr)) {
@@ -348,7 +354,7 @@ mesh_error_t WisunBorderRouter::set_radius_shared_secret(uint16_t shared_secret_
 mesh_error_t WisunBorderRouter::set_bbr_radius_shared_secret(void)
 {
     if (_shared_secret_len == 0 || _shared_secret == NULL) {
-        return MESH_ERROR_UNKNOWN;
+        return MESH_ERROR_NONE;
     }
 
     int status = ws_bbr_radius_shared_secret_set(_mesh_if_id, _shared_secret_len, (uint8_t *) _shared_secret);