Update optcarrot (#472)

Update optcarrot to mame/optcarrot@9c88f5f

Author: tekknolagi

benchmarks/optcarrot/lib/optcarrot/driver/sixel_video.rb

@@ -7,7 +7,7 @@ def init
       super
       @buff = "".b
       @line = "".b
-      @seq_setup = "\e[H\ePq"
+      @seq_setup = "\e[H\eP7q"
       print "\e[2J"
 
       @palette, colors = Driver.quantize_colors(@palette_rgb)

benchmarks/optcarrot/lib/optcarrot/ppu.rb

@@ -471,7 +471,6 @@ def poke_2007(_addr, data)
           @palette_ram[addr ^ 0x10] = data
           @output_color[addr ^ 0x10] = final
         end
-        @output_bg_color = @palette_ram[0] & 0x3f
       else
         addr &= 0x3fff
         if addr >= 0x2000
@@ -891,7 +890,7 @@ def run
 
     def dispose
       @run = false
-      raise 'PPU Fiber should have finished' unless @fiber.resume == :done
+      raise 'PPU Fiber should have finished' unless @fiber.nil? || @fiber.resume == :done
       @fiber = nil
     end