[phodav] build-sys: fix -Wabi won't warn about anything

[Marc-André Lureau <malureau src gnome org>]

commit ef776ae110b34074378607fe1d59f02d01679799
Author: Marc-André Lureau <marcandre lureau redhat com>
Date:   Fri Feb 22 11:53:29 2019 +0100

    build-sys: fix -Wabi won't warn about anything
    
    Signed-off-by: Marc-André Lureau <marcandre lureau redhat com>

 m4/manywarnings.m4 | 1 -
 1 file changed, 1 deletion(-)
---
diff --git a/m4/manywarnings.m4 b/m4/manywarnings.m4
index 3e6dd21..afbaba2 100644
--- a/m4/manywarnings.m4
+++ b/m4/manywarnings.m4
@@ -104,7 +104,6 @@ AC_DEFUN([gl_MANYWARN_ALL_GCC],
   gl_manywarn_set=
   for gl_manywarn_item in \
     -W \
-    -Wabi \
     -Waddress \
     -Waggressive-loop-optimizations \
     -Wall \