[dovecot/core] fc452e: imapc: Fix assert-crash on some connect failures

[GitHub]

  Branch: refs/heads/master
  Home:   https://github.com/dovecot/core
  Commit: fc452ed724837734a04214bc8f9f112c603b28f7
      https://github.com/dovecot/core/commit/fc452ed724837734a04214bc8f9f112c603b28f7
  Author: Timo Sirainen <timo.sirainen at dovecot.fi>
  Date:   2017-01-20 (Fri, 20 Jan 2017)

  Changed paths:
    M src/lib-storage/index/imapc/imapc-storage.c

  Log Message:
  -----------
  imapc: Fix assert-crash on some connect failures

imapc_storage_has_modseqs() causes imapc_client_get_capabilities() to be
called, which assert-crashes if there isn't a valid connection:

Panic: file imapc-client.c: line 438 (imapc_client_get_capabilities): assertion failed: (conn != NULL)