Missing the end pointer reference solves #5760

Exiting from the unescape call the content in buffer still contains the original string. The result of unescape elaboration works well, but the rest of the string is still there and in the printf in the main program infact is printed overlapped to the previous content.
TY MauroS for the hint.

sonoff/support.ino

@@ -353,7 +353,7 @@ char* Unescape(char* buffer, uint16_t* size)
     }
   }
   *size = end_size;
-
+  *write++ = 0;   // add the end string pointer reference
 //  AddLogBuffer(LOG_LEVEL_DEBUG, (uint8_t*)buffer, *size);
 
   return buffer;