libedit: raise the warning level to 3.

NetBSD has the warning level to 5 but that actually triggers -Wcast-qual.

lib/libedit/Makefile

@@ -7,6 +7,8 @@ LIB=	edit
 SHLIB_MAJOR=	7
 SHLIBDIR?= /lib
 
+WARNS?=	3
+
 OSRCS=	chared.c common.c el.c eln.c emacs.c fcns.c filecomplete.c help.c \
 	hist.c keymacro.c map.c chartype.c \
 	parse.c prompt.c read.c refresh.c search.c sig.c terminal.c tty.c vi.c
@@ -41,8 +43,6 @@ CFLAGS+= -I. -I${.CURDIR} -I${.CURDIR}/edit -DWIDECHAR
 #CFLAGS+= -DDEBUG_TTY -DDEBUG_KEY -DDEBUG_READ -DDEBUG -DDEBUG_REFRESH
 #CFLAGS+= -DDEBUG_PASTE -DDEBUG_EDIT
 
-WARNS?=	1
-
 SUBDIR= edit/readline
 
 AHDR=	vi.h emacs.h common.h