Header value misinterpreted as query param

[veegee]

When specifying a header option whose value ends with an =, bat incorrectly interprets that as a query param, even when escaped.

➜ bat GET :8001/v1/me/entity 'X-APIKey:asdfasdfa\='
GET /v1/me/entity?X-APIKey%3Aasdfasdfa%5C= HTTP/1.1
Host: localhost:8001
Accept: application/json
Accept-Encoding: gzip, deflate
User-Agent: bat/0.1.0

[ghost]

unfortunately this pr breaks queries with ":" into headers. I cannot think of away to fixes this without completely changing the parsing :weary: