Allow microdescs to be up to 2k. Partial fix for 6404.

changes/bug6404

@@ -0,0 +1,7 @@
+  o Minor bugfixes:
+
+    - Increase the maximum length of microdescriptor we are willing to
+      generate from 1K to 2K. Occasionally this is needed for routers
+      with complex policies or family declarations. Partial fix for
+      bug 6404; fix on 0.2.2.6-alpha.
+

src/or/dirvote.c

@@ -3502,7 +3502,7 @@ dirvote_create_microdescriptor(const routerinfo_t *ri)
 {
   microdesc_t *result = NULL;
   char *key = NULL, *summary = NULL, *family = NULL;
-  char buf[1024];
+  char buf[2048];
   size_t keylen;
   char *out = buf, *end = buf+sizeof(buf);