Rework adding one minute back-off level for all providers

(cherry picked from commit d8f314ff0ef64e8d90b21b7865e46be74db5e570)

src/NzbDrone.Core.Test/ThingiProviderTests/ProviderStatusServiceFixture.cs

@@ -161,7 +161,7 @@ namespace NzbDrone.Core.Test.ThingiProviderTests
             status.Should().NotBeNull();
 
             origStatus.EscalationLevel.Should().Be(3);
-            status.DisabledTill.Should().BeCloseTo(_epoch + TimeSpan.FromMinutes(1), _disabledTillPrecision);
+            status.DisabledTill.Should().BeCloseTo(_epoch + TimeSpan.FromMinutes(5), _disabledTillPrecision);
         }
     }
 }

src/NzbDrone.Core/ThingiProvider/Status/ProviderStatusServiceBase.cs

@@ -116,7 +116,7 @@ namespace NzbDrone.Core.ThingiProvider.Status
 
                 if (inStartupGracePeriod && minimumBackOff == TimeSpan.Zero && status.DisabledTill.HasValue)
                 {
-                    var maximumDisabledTill = now.AddSeconds(EscalationBackOff.Periods[1]);
+                    var maximumDisabledTill = now + TimeSpan.FromSeconds(EscalationBackOff.Periods[2]);
                     if (maximumDisabledTill < status.DisabledTill)
                     {
                         status.DisabledTill = maximumDisabledTill;