[libmicrohttpd] libmicrohttpd api change?

[Michael Vetter]

Hello!

For our project Profanity [1] (an XMPP client) we have a test framework
called stabber [2].

Stabber uses libmicrohttpd.

Our CI show [3] now that stabber doesn't build anymore on Debian
Testing, Arch Linux and Fedora.

It appears on Debian testing libmicrohttpd was updated to 0.9.71.
While on Debian stable (where stabber builds) 0.9.62 is used.

Is it possible that you did an API change in a minor release?
We get the following build failure:
https://travis-ci.org/github/profanity-im/profanity/jobs/705760514#L2123

```
libtool: compile:  gcc -DHAVE_CONFIG_H -I. -I./src
-I/usr/include/glib-2.0 -I/usr/lib/x86_64-linux-gnu/glib-2.0/include
-Wall -Wno-deprecated-declarations -Wunused -Werror -g -O2 -c
src/server/httpapi.c  -fPIC -DPIC -o src/server/.libs/httpapi.o

src/server/httpapi.c: In function 'httpapi_start':

src/server/httpapi.c:195:9: error: passing argument 5 of
'MHD_start_daemon' from incompatible pointer type
[-Werror=incompatible-pointer-types]

  195 |         &connection_cb,

      |         ^~~~~~~~~~~~~~

      |         |

      |         int (*)(void *, struct MHD_Connection *, const char *,
      const char *, const char *, const char *, size_t *, void **) {aka
      int (*)(void *, struct MHD_Connection *, const char *, const char
      *, const char *, const char *, long unsigned int *, void **)}

In file included from src/server/httpapi.c:36:

/usr/include/microhttpd.h:2425:1: note: expected
'MHD_AccessHandlerCallback' {aka 'enum MHD_Result (*)(void *, struct
MHD_Connection *, const char *, const char *, const char *, const char
*, long unsigned int *, void **)'} but argument is of type 'int
(*)(void *, struct MHD_Connection *, const char *, const char *, const
char *, const char *, size_t *, void **)' {aka 'int (*)(void *, struct
MHD_Connection *, const char *, const char *, const char *, const char
*, long unsigned int *, void **)'}

 2425 | MHD_start_daemon (unsigned int flags,

      | ^~~~~~~~~~~~~~~~

cc1: all warnings being treated as errors
```

1: https://github.com/profanity-im/profanity
2: https://github.com/profanity-im/stabber
3: https://travis-ci.org/github/profanity-im/profanity/builds/705760512

Best,
Michael

PS: Please include me in CC since I'm not subscribed to the mailinglist.