Add mid to observation store setContext.

Signed-off-by: Achim Kraus <achim.kraus@bosch-si.com>

californium-core/src/main/java/org/eclipse/californium/core/network/BaseMatcher.java

@@ -203,7 +203,7 @@ protected void failed() {
 
 				@Override
 				public void onContextEstablished(EndpointContext endpointContext) {
-					observationStore.setContext(token, endpointContext);
+					observationStore.setContext(token, request.getMID(), endpointContext);
 				}
 			});
 		}

californium-core/src/main/java/org/eclipse/californium/core/observe/InMemoryObservationStore.java

@@ -141,11 +141,13 @@ public void clear() {
 	}
 
 	@Override
-	public void setContext(Token token, final EndpointContext ctx) {
+	public void setContext(Token token, int mid, EndpointContext ctx) {
 
 		if (token != null && ctx != null) {
 			Observation obs = map.get(token);
 			if (obs != null) {
+				// though this implementation doesn't clone the request when put, 
+				// the mid doesn't need to be updated!
 				map.replace(token, obs, new Observation(obs.getRequest(), ctx));
 			}
 		}

californium-core/src/main/java/org/eclipse/californium/core/observe/ObservationStore.java

@@ -85,9 +85,10 @@ public interface ObservationStore {
 	 * </p>
 	 * 
 	 * @param token The token of the observation to set the context on.
+	 * @param mid assigned mid. The mid is usually not available, when the put is called.
 	 * @param endpointContext The context to set.
 	 */
-	void setContext(Token token, EndpointContext endpointContext);
+	void setContext(Token token, int mid, EndpointContext endpointContext);
 
 	void start();