Steps to reproduce:

1. Install official Docker CE
2. run Alpine 3.13/3.12:

   docker run -it alpine:3.12 /bin/sh
   docker run -it alpine:3.13 /bin/sh
   

3. install libssh-dev on both containers:

   apk add libssh-dev
   

4. check presence of the version string:

   on 3.13:
   cat /usr/include/libssh/libssh.h|grep -i LIBSSH_VERSION
   #include <libssh/libssh_version.h>
   on 3.12:
   cat /usr/include/libssh/libssh.h  | egrep \#define.*'LIBSSH_VERSION_MAJOR'
   #define LIBSSH_VERSION_MAJOR  0
   

5. check libssh.m4 used with Zabbix during configure step:

     if test "x$want_ssh" = "xyes"; then
        AC_MSG_CHECKING(for SSH support)
        if test "x$_libssh_dir" = "xno"; then
          if test -f /usr/include/libssh/libssh.h; then
            SSH_CFLAGS=-I/usr/include
            SSH_LDFLAGS=-L/usr/lib
            SSH_LIBS="-lssh"
            found_ssh="yes"
   	 LIBSSH_ACCEPT_VERSION([/usr/include/libssh/libssh.h])
          elif test -f /usr/local/include/libssh/libssh.h; then
            SSH_CFLAGS=-I/usr/local/include
            SSH_LDFLAGS=-L/usr/local/lib
            SSH_LIBS="-lssh"
            found_ssh="yes"
   	 LIBSSH_ACCEPT_VERSION([/usr/local/include/libssh/libssh.h])
          else #libraries are not found in default directories
            found_ssh="no"
            AC_MSG_RESULT(no)
          fi # test -f /usr/include/libssh/libssh.h; then
        else # test "x$_libssh_dir" = "xno"; then
          if test -f $_libssh_dir/include/libssh/libssh.h; then
   	 SSH_CFLAGS=-I$_libssh_dir/include
            SSH_LDFLAGS=-L$_libssh_dir/lib
            SSH_LIBS="-lssh"
            found_ssh="yes"
   	 LIBSSH_ACCEPT_VERSION([$_libssh_dir/include/libssh/libssh.h])
          else #if test -f $_libssh_dir/include/libssh/libssh.h; then
            found_ssh="no"
            AC_MSG_RESULT(no)
          fi #test -f $_libssh_dir/include/libssh/libssh.h; then
        fi #if test "x$_libssh_dir" = "xno"; then
     fi # if test "x$want_ssh" != "xno"; then
   
   ...
   
   AC_DEFUN([LIBSSH_ACCEPT_VERSION],
   [
   	# Zabbix minimal major supported version of libssh:
   	minimal_libssh_major_version=0
   	minimal_libssh_minor_version=6
   
   	# get the major version
   	found_ssh_version_major=`cat $1 | $EGREP \#define.*'LIBSSH_VERSION_MAJOR ' | $AWK '{print @S|@3;}'`
   	found_ssh_version_minor=`cat $1 | $EGREP \#define.*'LIBSSH_VERSION_MINOR ' | $AWK '{print @S|@3;}'`
   
   	if test $((found_ssh_version_major)) -gt $((minimal_libssh_major_version)); then
   		accept_ssh_version="yes"
   	elif test $((found_ssh_version_major)) -lt $((minimal_libssh_major_version)); then
   		accept_ssh_version="no"
   	elif test $((found_ssh_version_minor)) -ge $((minimal_libssh_minor_version)); then
   		accept_ssh_version="yes"
   	else
   		accept_ssh_version="no"
   	fi;
   ])dnl 
   

Result:
checking for SSH support... yes
configure: error: SSH library version requirement not met (>= 0.6.0)

Expected:
Correct configure/build procedure.