base64_decode doesn't properly ignore characters that aren't in base64_table.

Here's a patch to fix the problem.

--- base64.c.orig       Sat Feb 27 10:11:08 1999
+++ base64.c    Thu Jun 24 11:04:31 1999
@@ -97,10 +97,7 @@
        while ((ch = *current++) != '\0') {
                if (ch == base64_pad) break;
                chp = strchr(base64_table, ch);
-               if (chp == NULL) {
-                       efree(result);
-                       return NULL;
-               }
+               if (chp == NULL) continue;
                ch = chp - base64_table;
 
                switch(i % 4) {