build: fix travis build

.travis.yml

@@ -71,7 +71,7 @@ script:
   - make all
   - travis_retry make testfront
   - luajit $(which luacheck) --no-color -q frontend | tee ./luacheck.out
-  - test $(grep Total ./luacheck.out | awk '{print $2}') -le 65
+  - test $(grep Total ./luacheck.out | awk '{print $2}') -le 63
 
 after_success:
   - make coverage

frontend/device/kindle/device.lua

@@ -2,7 +2,7 @@ local Generic = require("device/generic/device")
 local DEBUG = require("dbg")
 
 local function yes() return true end
-local function no() return false end
+local function no() return false end  -- luacheck: ignore
 
 local Kindle = Generic:new{
     model = "Kindle",

frontend/ui/uimanager.lua

@@ -567,8 +567,8 @@ end
 
 function UIManager:initLooper()
     if DUSE_TURBO_LIB and not self.looper then
-        TURBO_SSL = true
-        __TURBO_USE_LUASOCKET__ = true
+        TURBO_SSL = true -- luacheck: ignore
+        __TURBO_USE_LUASOCKET__ = true -- luacheck: ignore
         local turbo = require("turbo")
         self.looper = turbo.ioloop.instance()
     end