Remove redundant "of a security vulnerability"

Author: bwateratmsft

SECURITY.MD

@@ -1,10 +1,10 @@
-<!-- BEGIN MICROSOFT SECURITY.MD V0.0.4 BLOCK -->
+<!-- BEGIN MICROSOFT SECURITY.MD V0.0.5 BLOCK -->
 
 ## Security
 
 Microsoft takes the security of our software products and services seriously, which includes all source code repositories managed through our GitHub organizations, which include [Microsoft](https://github.com/Microsoft), [Azure](https://github.com/Azure), [DotNet](https://github.com/dotnet), [AspNet](https://github.com/aspnet), [Xamarin](https://github.com/xamarin), and [our GitHub organizations](https://opensource.microsoft.com/).
 
-If you believe you have found a security vulnerability in any Microsoft-owned repository that meets Microsoft's [Microsoft's definition of a security vulnerability](https://docs.microsoft.com/en-us/previous-versions/tn-archive/cc751383(v=technet.10)) of a security vulnerability, please report it to us as described below.
+If you believe you have found a security vulnerability in any Microsoft-owned repository that meets Microsoft's [Microsoft's definition of a security vulnerability](https://docs.microsoft.com/en-us/previous-versions/tn-archive/cc751383(v=technet.10)), please report it to us as described below.
 
 ## Reporting Security Issues