update.sh: Move map screenshots to ctf_map/textures/ (#411)

mods/ctf/ctf_map/schem_map.lua

@@ -241,7 +241,7 @@ local function load_maps()
 				if extension == "mts" then
 					files_hash[dir .. "/" .. filename] = true
 				else
-					if extension ~= "conf" and extension ~= "md"
+					if extension ~= "conf" and extension ~= "md" and extension ~= "png"
 							and files[i] ~= ".git" then
 						error("Map extension is not '.mts': " .. files[i])
 					end

update.sh

@@ -5,5 +5,6 @@ cd ../crafting &&
 git pull origin master &&
 cd ../ctf/ctf_map/maps &&
 git pull origin master &&
+cp ./*.png ../textures/ &&
 cd ../../../.. &&
 ./build.sh ../games/capturetheflag