bug#34763: 27.0.50; url-retrieve-synchronously misbehaves inside eldoc-documentation-function

[Dmitry Gutov]

And regardless of whether the slowdown is caused by external factors in 
my examples, here are two aspects that worry me either way:

1. When I get to "Transfer interrupted", I need to press 'C-g' a second 
time to actually abort right away.

2. When that happens, 'M-x list-processes' shows an extra new line with 
status 'open'. Interrupt enough requests this way - and there are many 
such lines there. That doesn't look good.