package/berkeleydb: fix non-threaded build

Building berkeleydb is broken with a non-threaded toolchain with gcc >=
14.x:

../src/rep/rep_method.c:1740:25: error: implicit declaration of function
 '__repmgr_get_nsites'; did you mean '__rep_get_nsites'?
 [-Wimplicit-function-declaration]
 1740 |                 return (__repmgr_get_nsites(env, n));

According to src/repmgr/repmgr_util.c, line 503+, the function
'__repmgr_get_nsites' mentioned in the gcc error message "may only be
called after threads have been started".
This source file repmgr_util.c belongs to REPMGR_OBJS according to
dist/Makefile.in, line 249+, which is, according to dist/configure.ac,
line 956, only build if thread support is present.

In a non-threaded build '__repmgr_get_nsites' does not exist causing the
build error.

To fix the build error we disable replication for non-threaded
toolchains.

Using gcc 13.x the build error does not occur, tested with this
defconfig:

BR2_TOOLCHAIN_BUILDROOT_UCLIBC=y
BR2_PTHREADS_NONE=y
BR2_GCC_VERSION_13_X=y
BR2_PACKAGE_BERKELEYDB=y

Using this minimal gcc 14.x-based defconfig

BR2_TOOLCHAIN_BUILDROOT_UCLIBC=y
BR2_PTHREADS_NONE=y
BR2_PER_PACKAGE_DIRECTORIES=y
BR2_PACKAGE_BERKELEYDB=y

the build error can be reproduced.

The oldest build error of this kind, afaics, dates back to 2024-06-13:
https://autobuild.buildroot.net/results/e0d/e0d6bdbef01bee277b0da83605b2906af876058a/

Fixes:
https://autobuild.buildroot.net/results/792/792ed942d17bb8d00cd321536a102f6dd63b6a8a/

Signed-off-by: Bernd Kuhls <bernd@kuhls.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/berkeleydb/berkeleydb.mk

@@ -45,6 +45,7 @@ define BERKELEYDB_CONFIGURE_CMDS
 		--with-pic \
 		--enable-o_direct \
 		$(if $(BR2_TOOLCHAIN_HAS_THREADS),--enable-mutexsupport,--disable-mutexsupport) \
+		$(if $(BR2_TOOLCHAIN_HAS_THREADS),--enable-replication,--disable-replication) \
 	)
 endef