davfs2: fix compile issue

package/davfs2/patches/patch-src_Makefile_in

@@ -0,0 +1,12 @@
+--- davfs2-1.5.2.orig/src/Makefile.in	2014-08-23 20:13:17.000000000 +0200
++++ davfs2-1.5.2/src/Makefile.in	2016-09-24 10:24:45.225043359 +0200
+@@ -248,8 +248,7 @@ mount_davfs_SOURCES = cache.c dav_coda.c
+         kernel_interface.h mount_davfs.h webdav.h
+ 
+ umount_davfs_SOURCES = umount_davfs.c defaults.h
+-AM_CFLAGS = -Wall -Werror=format-security \
+-        -fstack-protector --param=ssp-buffer-size=4
++AM_CFLAGS = 
+ 
+ all: all-am
+