Nanostack: release connect_semaphore only when it is pending

Only release if the current _connect_status is CONNECTING. If the semaphore is released many times for each connect, then the next connect will not wait(), as it will be able to decrement the semaphore imediatelly.

Author: michalpasztamobica

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

@@ -120,8 +120,8 @@ nsapi_error_t MeshInterfaceNanostack::initialize(NanostackRfPhy *phy)
 void Nanostack::Interface::network_handler(mesh_connection_status_t status)
 {
     if (_blocking) {
-        if (status == MESH_CONNECTED || status == MESH_CONNECTED_LOCAL ||
-                status == MESH_CONNECTED_GLOBAL) {
+        if (_connect_status == NSAPI_STATUS_CONNECTING && (status == MESH_CONNECTED
+                || status == MESH_CONNECTED_LOCAL || status == MESH_CONNECTED_GLOBAL)) {
             connect_semaphore.release();
         } else if (status == MESH_DISCONNECTED) {
             disconnect_semaphore.release();