Only look for libedit package if it is not native to the system

(...or something.  Needless to say, somebody with autocrap clue should
stare at this in disbelief.)

configure.ac

@@ -140,7 +140,11 @@ fi
 AC_SUBST(PCRE_CFLAGS)
 AC_SUBST(PCRE_LIBS)
 
-PKG_CHECK_MODULES([LIBEDIT], [libedit], 
+AC_CHECK_HEADERS([edit/readline/readline.h],
+	[AC_DEFINE([HAVE_LIBEDIT], [1], [Define if we have libedit])
+	LIBEDIT_LIBS="-ledit"],
+
+	[PKG_CHECK_MODULES([LIBEDIT], [libedit], 
 		# having the module does not imply having the header
 		[AC_CHECK_HEADERS([editline/readline.h],
 				  [AC_DEFINE([HAVE_LIBEDIT], [1], [Define if we have libedit])],
@@ -160,12 +164,12 @@ PKG_CHECK_MODULES([LIBEDIT], [libedit],
 		 fi
 		 LIBEDIT_LIBS="$ax_cv_lib_readline"
 		])
+	])
 
 # Checks for header files.
 AC_HEADER_STDC
 AC_HEADER_SYS_WAIT
 AC_HEADER_TIME
-AC_CHECK_HEADERS([edit/readline/readline.h])
 AC_CHECK_HEADERS([sys/param.h])
 AC_CHECK_HEADERS([sys/types.h])
 AC_CHECK_HEADERS([sys/endian.h])