## What does this PR do?
This should fix#3164.
The problem is that `httpx` keeps making breaking changes to their library, so we just have to adjust the code a little bit to make it work with the new version of the library.
## Related issues
Closes #3164
* [mod] /image_proxy: don't decompress images
* [fix] image_proxy: always close the httpx respone
previously, when the content type was not an image and some other error,
the httpx response was not closed
* [mod] /image_proxy: use HTTP/1 instead of HTTP/2
httpx: HTTP/2 is slow when a lot data is downloaded.
https://github.com/dalf/pyhttp-benchmark
also, the usage of HTTP/1 decreases the load average
* [mod] searx.utils.dict_subset: rewrite with comprehension
Co-authored-by: Alexandre Flament <alex@al-f.net>
* searx.network.client.LOOP is initialized in a thread
* searx.network.__init__ imports LOOP which may happen
before the thread has initialized LOOP
This commit adds a new function "searx.network.client.get_loop()"
to fix this issue
settings.yml:
* outgoing.networks:
* can contains network definition
* propertiers: enable_http, verify, http2, max_connections, max_keepalive_connections,
keepalive_expiry, local_addresses, support_ipv4, support_ipv6, proxies, max_redirects, retries
* retries: 0 by default, number of times searx retries to send the HTTP request (using different IP & proxy each time)
* local_addresses can be "192.168.0.1/24" (it supports IPv6)
* support_ipv4 & support_ipv6: both True by default
see https://github.com/searx/searx/pull/1034
* each engine can define a "network" section:
* either a full network description
* either reference an existing network
* all HTTP requests of engine use the same HTTP configuration (it was not the case before, see proxy configuration in master)
Marc Abonce Seguin
Noémi Ványi
Alexandre Flament