Use the csrf header name MegaRAC actually checks

The web session helper sent X-CSRF-Token. MegaRAC checks X-CSRFTOKEN, so the
login succeeded and then every request answered Invalid Authentication, which is
why this helper has never worked. Confirmed both ways against a bmc: the same
request answers 401 with the old spelling and 200 with the new one.

confluent_server/aiohmi/redfish/oem/ami/megarac.py

@@ -168,6 +168,8 @@ class OEMHandler(generic.OEMHandler):
             raise Exception('Failed to authenticate to BMC')
         if 'CSRFToken' in rsp:
             self.csrftok = rsp['CSRFToken']
-            wc.set_header('X-CSRF-Token', rsp['CSRFToken'])
+            # The header MegaRAC checks is spelled without separators; with
+            # X-CSRF-Token every subsequent call answers Invalid Authentication
+            wc.set_header('X-CSRFTOKEN', rsp['CSRFToken'])
         self._wc = wc
         return wc