Missing returns for inarray and countinarray (#3295)

Added some return cases if empty arrays are given to these two commands.

Thanks to @sader1992

src/map/script.cpp

@@ -6415,6 +6415,12 @@ BUILDIN_FUNC(inarray)
 
 	array_size = script_array_highest_key(st, sd, name, ref) - 1;
 
+	if (array_size < 0)
+	{
+		script_pushint(st, -1);
+		return SCRIPT_CMD_SUCCESS;
+	}
+
 	if (array_size > SCRIPT_MAX_ARRAYSIZE)
 	{
 		ShowError("buildin_inarray: The array is too large.\n");
@@ -6497,6 +6503,12 @@ BUILDIN_FUNC(countinarray)
 	array_size1 = script_array_highest_key(st, sd, name1, ref1) - 1;
 	array_size2 = script_array_highest_key(st, sd, name2, ref2) - 1;
 
+	if (array_size1 < 0 || array_size2 < 0)
+	{
+		script_pushint(st, 0);
+		return SCRIPT_CMD_SUCCESS;
+	}
+
 	if (array_size1 > SCRIPT_MAX_ARRAYSIZE || array_size2 > SCRIPT_MAX_ARRAYSIZE)
 	{
 		ShowError("buildin_countinarray: The array is too large.\n");