Fixed module's table not updating in lume.hotswap()

Changed the returned values from pcall() in lume.hotswap() to be handled
correctly -- the second return value being the wrapped-function's first
return value. This bug would effect hotswapped modules which used the
modern approach of returning a table rather than creating globals.

lume.lua

@@ -266,12 +266,13 @@ function lume.hotswap(modname)
       if type(v) == "table" then update(old[k], v) else old[k] = v end
     end
   end
-  local oldmod = pcall(require, modname) or nil
   local err = nil
   local function onerror(e)
     for k, v in pairs(_G) do _G[k] = oldglobal[k] end
     err = lume.trim(e)
   end
+  local ok, oldmod = pcall(require, modname)
+  oldmod = ok and oldmod or nil
   xpcall(function()
     package.loaded[modname] = nil
     local newmod = require(modname)