Empty header in headers list results in SyntaxError: Failed to execute 'setRequestHeader'

[vadistic]

Describe the bug
When the empty header is present in headers list in graphql tab any call results in syntaxt error.

// response field
SyntaxError: Failed to execute 'setRequestHeader' on 'XMLHttpRequest': '' is not a valid HTTP header field name.. Check console for details.

// console
Error DOMException: Failed to execute 'setRequestHeader' on 'XMLHttpRequest': '' is not a valid HTTP header field name.
    at https://postwoman.io/_nuxt/be6fd6eac58c44d1d090.js:2:162095
    at Object.h [as forEach] (https://postwoman.io/_nuxt/be6fd6eac58c44d1d090.js:2:73192)
    at https://postwoman.io/_nuxt/be6fd6eac58c44d1d090.js:2:162011
    at new Promise (<anonymous>)
    at t.exports (https://postwoman.io/_nuxt/be6fd6eac58c44d1d090.js:2:160865)
    at t.exports (https://postwoman.io/_nuxt/be6fd6eac58c44d1d090.js:2:184050)

To Reproduce

1. Go to https://postwoman.io/graphql
2. Add some valid query + header (eg. Authorization)
3. Click "Add new" to add empty header
4. Smash green execute button
5. See error

Expected behavior
I would expect empty headers to be ignored.

I think it's quite common to e.g. add header an forgot about it later, or click "Add header" too many times - when testing something on the run - which I believe what postwoman is for.

In case empty header field is no-go, then I would expect this error to be handled.

I've searched for a bit, but I do not believe there's issue about it - so I thought I would let you know

Cheers!