fix: request uri build handling of + in template

Fix #33

Author: StarlightIbuki

src/resty/aws/request/build.lua

@@ -100,7 +100,7 @@ local function build_request(operation, config, params)
  -- print(name," = ", param_value, ": ",location, " (", locationName,")")
 
  if location == "uri" then
- local place_holder = "{" .. locationName .. "}"
+ local place_holder = "{" .. locationName .. "%+?}"
  request.path = request.path:gsub(place_holder, param_value)
 
  elseif location == "querystring" then