w3m: add workaround for segfault for dump_source/dump_extra

This avoids passing NULL to a function that clearly can't deal with it.
It probably isn't correct, but at least it doesn't crash.

reported by Jon Fineman
ok jca

www/w3m/Makefile

@@ -2,6 +2,7 @@ COMMENT=	pager/text-based web browser
 
 DIST_TUPLE=	srht rkta w3m 36005bf6ef17b0094e0c67a280edb5046383208d .
 PKGNAME=	w3m-0.5.3pl20241116
+REVISION=	0
 
 CATEGORIES=	www
 

www/w3m/patches/patch-file_c

@@ -0,0 +1,12 @@
+Index: file.c
+--- file.c.orig
++++ file.c
+@@ -2225,6 +2225,8 @@ loadGeneralFile(char *path, ParsedURL *volatile curren
+     }
+     else if (w3m_dump & DUMP_FRAME)
+ 	return NULL;
++    else
++	proc = NULL;
+ 
+     if (t_buf == NULL)
+ 	t_buf = newBuffer(INIT_BUFFER_WIDTH);