system/vlock: Fix build for -current.

Signed-off-by: B. Watson <yalhcru@gmail.com>

system/vlock/vlock.SlackBuild

@@ -27,6 +27,8 @@
 #  OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 #  ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+# 20170621 bkw: fix build on -current.
+
 # 20170309 bkw:
 # - take over maintenance
 # - i486 => i586
@@ -83,6 +85,10 @@ find -L . \
  \( -perm 666 -o -perm 664 -o -perm 640 -o -perm 600 -o -perm 444 \
  -o -perm 440 -o -perm 400 \) -exec chmod 644 {} \;
 
+# recent libcaca in -current no longer has the compatibility symlink
+# cucul.h => caca.h, so:
+sed -i 's,<cucul.h>,<caca.h>,' modules/caca.c
+
 # patch by B. Watson, fixes the shell script wrapper so it loads
 # the caca plugin when the -t/--timeout option is passed.
 patch -p1 < $CWD/fix_caca.diff