Patch from Colin Watson intended to give a clean Unix compile with GCC 4.

(Since we choose to compile with -Werror, this is particularly important.)

I haven't yet checked that the resulting source actually compiles cleanly with
GCC 4, hence not marking `gcc4-warnings' as fixed just yet.

[originally from svn r7041]

sshzlib.c

@@ -224,6 +224,7 @@ static void lz77_compress(struct LZ77Context *ctx,
     }
     st->npending -= i;
 
+    defermatch.distance = 0; /* appease compiler */
     defermatch.len = 0;
     deferchr = '\0';
     while (len > 0) {