Regex Example for bypassList entry is Incorrect

### Type of issue

Missing information

### Description

The example regex is incorrect as it does not match **all** servers in the contoso.com domain. It will not match urls such as www1.contoso.com or dev1.contoso.com

recommend changing it to something like:
`[a-zA-Z0-9_-]+\.contoso\.com$`

### Page URL

https://learn.microsoft.com/en-us/dotnet/framework/configure-apps/file-schema/network/defaultproxy-element-network-settings

### Content source URL

https://github.com/dotnet/docs/blob/main/docs/framework/configure-apps/file-schema/network/defaultproxy-element-network-settings.md

### Document Version Independent Id

1a610214-183b-0328-744a-90161d572aa1

### Article author

@karelz

### Metadata

* ID: 9079251a-98f0-5711-9cca-6352e98dec61
* Service: **dotnet-framework**
* Sub-service: **networking**