Error: specified session has been invalidated for some reason.

I've just rotated my certificates on my taskserver. After updating /home/judson/.task/keys/ca.cert to fix a TLS handshake issue, I now have the situation described here.

#### To report a bug...

* What command(s) did you run?

task sync

* What did you expect to happen?

normal sync

* What actually happened?

```
Syncing with tasks.madhelm.net:53589

The specified session has been invalidated for some reason.
Sync failed. Could not connect to the Taskserver.
```

* Paste the output of the ```task diag``` command.

Client
```
task 2.5.1
Platform: Linux

Compiler
Version: 7.4.0
Caps: +stdc +stdc_hosted +LP64 +c8 +i32 +l64 +vp64 +time_t64
Compliance: C++11

Build Features
Built: Feb 24 2016 22:18:22
CMake: 3.13.4
libuuid: libuuid + uuid_unparse_lower
libgnutls: 3.6.7
Build type: Release

Configuration
File: /home/judson/.taskrc (found), 429 bytes, mode 100444
Data: /home/judson/.local/share/task (found), dir, mode 40755
Locking: Enabled
GC: Enabled
$EDITOR: /home/judson/.nix-profile/bin/nvim
Server: tasks.madhelm.net:53589
CA: /home/judson/.task/keys/ca.cert, readable, 3156 bytes
Trust: strict
Certificate: /home/judson/.task/keys/public.cert, readable, 3557 bytes
Key: /home/judson/.task/keys/private.key, readable, 6253 bytes
Ciphers: NORMAL
Creds: madhelm/judson/************************************

Hooks
System: Enabled
Location: /home/judson/.local/share/task/hooks
(-none-)

Tests
$TERM: screen-256color (232x61)
Dups: Scanned 251 tasks for duplicate UUIDs:
No duplicates found
Broken ref: Scanned 251 tasks for broken references:
No broken references found
```

Server
```
taskd 1.1.0
Platform: Linux
Hostname: webserver

Compiler
Version: 7.4.0
Caps: +stdc +stdc_hosted +200809 +200809 +LP64 +c8 +i32 +l64 +vp64 +time_t64
Compliance: C++11

Build Features
Built: May 10 2015 21:35:25
CMake: 3.13.4
libuuid: libuuid + uuid_unparse_lower
libgnutls: 3.6.7
Build type: Release

Configuration
TASKDDATA:
root: /var/lib/taskserver (readable)
config: /var/lib/taskserver/config (readable)
CA: /var/lib/acme/tasks.madhelm.net/chain.pem (readable)
Certificate: /var/lib/acme/tasks.madhelm.net/cert.pem (readable)
Key: /var/lib/acme/tasks.madhelm.net/key.pem (readable)
CRL: /var/lib/acme/tasks.madhelm.net/server.crl
Log: /tmp/taskd.log (missing)
PID File: /tmp/taskd.pid (missing)
Server:
Max Request: 1048576 bytes
Ciphers:
Trust: strict
```