LMMS quits unexpectedly when loading a project that uses Carla Rack with Carla 2.3.0-alpha1

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### Bug Summary
LMMS quits itself when loading a project that is using Carla Rack (with Carla 2.3.0-alpha1 installed) or in a blank project, when trying to drag and drop to create a new track with Carla Rack or Patchbay.
LMMS was loading the project fine since yesterday. After, I've received an update of Carla and since then LMMS started to crash with the attached log.

#### Steps to reproduce
Load any project that uses Carla Rack and have Carla 2.3.0-alpha1 installed.

#### Expected behavior
To LMMS load the project or create a Carla Rack track correctly and don't crash.

#### Actual behavior
LMMS is quitting unexpectedly.

#### Screenshot

#### Affected LMMS versions
lmms-1.2.2-linux-x86_64.AppImage

Running LMMS in Ubuntu 19.10.
Running `carla --version` shows me the following information:
```
Using Carla version 2.3.0-alpha1
Python version: 3.7.5
Qt version: 5.12.4
PyQt version: 5.12.3
Binary dir: /usr/lib/carla
Resources dir: /usr/share/carla/resources
```

#### Logs

Click to expand

Carla appears to be installed on this system at /usr/lib[64]/carla so we'll use it.

Jack appears to be installed on this system, so we'll use it.

Starting using X11Embed protocol.

unique ID: FV2l

RemotePlugin::DebugMessage: inputs: 2  output: 2

RemotePlugin::DebugMessage: creating editor

RemotePlugin::DebugMessage: editor successfully created

Starting using X11Embed protocol.

unique ID: FV2l

RemotePlugin::DebugMessage: inputs: 2  output: 2

RemotePlugin::DebugMessage: creating editor

RemotePlugin::DebugMessage: editor successfully created

/tmp/.mount_lmms-1IbqAnR/usr/bin/lmms.real: symbol lookup error: /tmp/.mount_lmms-1IbqAnR/usr/lib/lmms/libcarlabase.so: undefined symbol: carla_get_library_filename

Start by reproducing the crash while loading a project with Carla Rack or creating a Carla Rack/Patchbay track, using Carla 2.3.0-alpha1 and the reported LMMS AppImage. Inspect the libcarlabase.so integration around the reported undefined symbol, then verify that LMMS loads the project and creates the track without quitting.

Written by the indexing model from the issue text.