Add NULL termination to payloads

Messages addressed to "this" node, will have a null char
appended to the payload after message verification is
done, because some "getters" assume the message being a
string.

libraries/MySensors/MySensor.cpp

@@ -620,6 +620,7 @@ boolean MySensor::process() {
 	if (destination == nc.nodeId) {
 		// This message is addressed to this node
 		mSetSigned(msg,0);
+		msg.data[mGetLength(msg)] = '\0'; // Add NULL termination so that "getters" works as expected
 
 		if (repeaterMode && last != nc.parentNodeId) {
 			// Message is from one of the child nodes. Add it to routing table.

libraries/MySensors/Version.h

@@ -6,6 +6,6 @@
 #ifndef Version_h
 #define Version_h
 
-#define LIBRARY_VERSION "1.5.3"
+#define LIBRARY_VERSION "1.5.4"
 
 #endif