Build failure with gpgme-1.18.0

[Sam James]

Hi,

gpgme-1.18.0 dropped a bunch of internal symbols,
including progress_callback (see e.g. callbacks.h
which has a comment at the top saying it's internal).

Unfortunately, this is what LibreOffice uses to detect [0]
gpgme:
```
# progress_callback is the only func with plain C linkage
# checking for it also filters out older, KDE-dependent libgpgmepp versions
AC_CHECK_LIB(gpgmepp, progress_callback, [ GPGMEPP_LIBS=-lgpgmepp ],
[AC_MSG_ERROR(gpgmepp not found or not functional)], [])
```

Originally reported downstream in Gentoo at https://bugs.gentoo.org/865321.

As a result, LibreOffice fails to build with newer gpgme:
```
checking for gpgme++/gpgmepp_version.h... yes
checking for progress_callback in -lgpgmepp... no
configure: error: gpgmepp not found or not functional
```

And from config.log:
```
configure:40830: checking for progress_callback in -lgpgmepp
configure:40853: x86_64-pc-linux-gnu-gcc -o conftest -pipe -march=native -fno-diagnostics-color -O2 -I/usr/include/python3.10     -Wl,-O1 -Wl,--as-needed -Wl,--defsym=__gentoo_check_ldflags__=0   conftest.c -lgpgmepp   >&5
/usr/lib/gcc/x86_64-pc-linux-gnu/12.1.1/../../../../x86_64-pc-linux-gnu/bin/ld: /var/tmp/portage/app-office/libreoffice-7.3.5.2/temp/ccH6cG0Y.o: in function `main':
conftest.c:(.text.startup+0x7): undefined reference to `progress_callback'
collect2: error: ld returned 1 exit status
configure:40853: $? = 1
```

[0] https://github.com/LibreOffice/core/blob/master/configure.ac#L12566

Best,
sam
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