Merge ~troyanov/maas:backport-95705c9-3.5 into maas:3.5

[Anton Troyanov]

fix: MAAS Redfish doesn't reboot Cisco UCS C-series appliance

Resolves LP:2028000

(cherry picked from commit 95705c9a4d264efe85e472629065b59b714ee0c6)

[Anton Troyanov (troyanov)]

review: Approve

diff --git a/src/provisioningserver/drivers/power/redfish.py b/src/provisioningserver/drivers/power/redfish.py
index d7e781c..e46d930 100644
--- a/src/provisioningserver/drivers/power/redfish.py
+++ b/src/provisioningserver/drivers/power/redfish.py
@@ -61,7 +61,7 @@ class RedfishPowerDriverBase(PowerDriver):
                 b"User-Agent": [b"MAAS"],
                 b"Accept": [b"application/json"],
                 b"Authorization": [b"Basic " + authorization],
-                b"Content-Type": [b"application/json; charset=utf-8"],
+                b"Content-Type": [b"application/json"],
             }
         )
 
diff --git a/src/provisioningserver/drivers/power/tests/test_redfish.py b/src/provisioningserver/drivers/power/tests/test_redfish.py
index fa1251c..d0e44d5 100644
--- a/src/provisioningserver/drivers/power/tests/test_redfish.py
+++ b/src/provisioningserver/drivers/power/tests/test_redfish.py
@@ -202,7 +202,7 @@ class TestRedfishPowerDriver(MAASTestCase):
             b"User-Agent": [b"MAAS"],
             b"Accept": [b"application/json"],
             b"Authorization": [b"Basic " + authorization],
-            b"Content-Type": [b"application/json; charset=utf-8"],
+            b"Content-Type": [b"application/json"],
         }
         driver = RedfishPowerDriver()
         headers = driver.make_auth_headers(power_user, power_pass)