Iterate passed parameter lists in correct order

We were using reverse iteraters, which, among other things, swapped the
keys and values.

Change-Id: I9dc18c6f4c75bcf5bc12e2a8245f74b49b12a0b5
Test: Verified via weaved
Bug: 27774023
diff --git a/libwebserv/binder_request_impl.cc b/libwebserv/binder_request_impl.cc
index b0042de..2a81e29 100644
--- a/libwebserv/binder_request_impl.cc
+++ b/libwebserv/binder_request_impl.cc
@@ -31,15 +31,15 @@
   CHECK(!(query_params.size() % 2));
   CHECK(!(post_params.size() % 2));
 
-  for (auto it = headers.crbegin(); it != headers.crend(); it += 2) {
+  for (auto it = headers.cbegin(); it != headers.cend(); it += 2) {
     headers_.emplace(*it, *(it + 1));
   }
 
-  for (auto it = query_params.crbegin(); it != query_params.crend(); it += 2) {
+  for (auto it = query_params.cbegin(); it != query_params.cend(); it += 2) {
     get_data_.emplace(*it, *(it + 1));
   }
 
-  for (auto it = post_params.crbegin(); it != post_params.crend(); it += 2) {
+  for (auto it = post_params.cbegin(); it != post_params.cend(); it += 2) {
     post_data_.emplace(*it, *(it + 1));
   }
 }