Merge pull request MicrosoftDocs#1153 from nschonni/typo-Diagnsotic

typo: Diagnsotic -> Diagnostic

Author: sptramer

docs-conceptual/azurermps-4.4.1/migration-guide.4.0.0.md

@@ -175,7 +175,7 @@ $a = $s1.NewResource.ServiceBusRuleId
 ```
 
 ### Set-AzureRmDiagnosticSettings
-- The command is going to be renamed to `Update-AzureRmDiagnsoticSettings`
+- The command is going to be renamed to `Update-AzureRmDiagnosticSettings`
 
 ```powershell-interactive
 # Old