Remove unused external variables

These variables are not used in these modules. Thus, there is no
need for the linker to link these variables here.

The s variable is unused since commit eab1a71d.
And the s variable disapeared in commit 00bdf989.
Signed-off-by: Guilherme Maciel Ferreira <guilherme.maciel.ferreira@gmail.com>

src/MQTTAsync.c

@@ -68,8 +68,6 @@ char* client_version_eye = "MQTTAsyncV3_Version " CLIENT_VERSION;
 #define min(a, b) (((a) < (b)) ? (a) : (b))
 #endif
 
-extern Sockets s;
-
 static ClientStates ClientState =
 {
 	CLIENT_VERSION, /* version */

src/MQTTProtocolOut.c

@@ -33,7 +33,6 @@
 #include "StackTrace.h"
 #include "Heap.h"
 
-extern MQTTProtocol state;
 extern ClientStates* bstate;