Change Session Cookie name

We have a use case where the GUI sits behind a Apache Tomcat proxy[1].

In this environment the cookie looks like:
```
en-US,en;q=0.9cookie:
JSESSIONIDSSO=4E999D77EF4E01CB72DE63949D5FF830;
CCFWSESSION=48A66EB93C00AD4F6327FB3FC2A338FC; LOGIN_MODE=Dashboard;
XSRF-TOKEN=Ue1La3Ik48Bn5NosyLnJ; SESSION=pCAdqApWt4Kb4IUV9vh8dnt:
```

The bmcweb code thinks the CCFWSESSION= is the SESSION. The bmcweb code
could be made smarter to differentiate "CCFWSESSION" and "SESSION" but
reading SESSION seems too generic of a name and something like
"BMCWEB-SESSION" better matches [2], [3], and [4].

[1]: https://tomcat.apache.org/tomcat-9.0-doc/proxy-howto.html
[2]: https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Set-Cookie#session_cookie
[3]: https://http.dev/set-cookie
[4]: https://www.geeksforgeeks.org/http-headers-set-cookie/

Tested: The GUI works and this proxy environment now works.

Change-Id: I9b63093c1839e26602fe26313a330e337961cb81
Signed-off-by: Gunnar Mills <gmills@us.ibm.com>
diff --git a/include/authentication.hpp b/include/authentication.hpp
index ba4fb44..3d026f3 100644
--- a/include/authentication.hpp
+++ b/include/authentication.hpp
@@ -143,7 +143,7 @@
     {
         std::string_view cookieValue = it->value();
         BMCWEB_LOG_DEBUG("Checking cookie {}", cookieValue);
-        auto startIndex = cookieValue.find("SESSION=");
+        auto startIndex = cookieValue.find("BMCWEB-SESSION=");
         if (startIndex == std::string::npos)
         {
             BMCWEB_LOG_DEBUG(
@@ -151,7 +151,7 @@
                 cookieValue);
             continue;
         }
-        startIndex += sizeof("SESSION=") - 1;
+        startIndex += sizeof("BMCWEB-SESSION=") - 1;
         auto endIndex = cookieValue.find(';', startIndex);
         if (endIndex == std::string::npos)
         {