Remove deprecated string-based API

Author: michalpasztamobica

main.cpp

@@ -89,10 +89,11 @@ int main()
         return error;
     }
 
-    while (NULL == mesh->get_ip_address())
+    SocketAddress sockAddr;
+    while (NSAPI_ERROR_OK != mesh->get_ip_address(&sockAddr))
         ThisThread::sleep_for(500);
 
-    printf("Connected. IP = %s\n", mesh->get_ip_address());
+    printf("Connected. IP = %s\n", sockAddr.get_ip_address());
 
 #if MBED_CONF_APP_ENABLE_LED_CONTROL_EXAMPLE
     // Network found, start socket example

mbed-os.lib

@@ -1 +1 @@
-https://github.com/ARMmbed/mbed-os/#679d24833acf0a0b5b0d528576bb37c70863bc4e
+https://github.com/ARMmbed/mbed-os/#888dfffabf9e77320ca0de5f2139f8b204043adc