fix compile warnings

include/tools.h

@@ -37,6 +37,7 @@ uint32_t fast_rand ();
 uint64_t splitmix64 (uint64_t state);
 
 #ifdef ESP_PLATFORM
+  #include "esp_timer.h"
   #define get_program_time esp_timer_get_time
 #else
   int64_t get_program_time ();

src/packets.c

@@ -1017,6 +1017,7 @@ int sc_removeEntity (int client_fd, int entity_id) {
   writeByte(client_fd, 1);
   writeVarInt(client_fd, entity_id);
 
+  return 0;
 }
 
 // S->C Registry Data (multiple packets) and Update Tags (configuration, multiple packets)