Fix incorrect last_joy value on game start causing initial movement when no input is pressed since GBDK2020v4
#include "ScriptRunner.h"
UBYTE joy = 0;
-UBYTE last_joy;
-UBYTE recent_joy;
-UBYTE await_input;
+UBYTE last_joy = 0;
+UBYTE recent_joy = 0;
+UBYTE await_input = 0;
UBYTE input_wait = 0;
BankPtr input_script_ptrs[NUM_INPUTS];
UBYTE input_script_persist = 0;
