Crash in scr_test

[st3fan]

* thread #1, queue = 'com.apple.main-thread', stop reason = EXC_BAD_ACCESS (code=1, address=0x400)
    frame #0: 0x0000000100007355 scr_test`scr_render_character(scr=0x000000010050f440, row=<unavailable>, column=0, flash=true) at scr.c:44 [opt]
   41  	static inline void scr_render_character(struct scr_t *scr, int row, int column, bool flash) {
   42  	   uint16_t base = (scr->two->screen_page == EWM_A2P_SCREEN_PAGE1) ? 0x0400 : 0x0800;
   43  	   uint8_t c = scr->two->cpu->ram[((txt_line_offsets[row] + base) + column)];
-> 44  	   if (scr->chr->textures[c] != NULL) {
   45  	      SDL_Rect dst;
   46  	      dst.x = column * 21;
   47  	      dst.y = row * 24;