Fix event url in description

Ghost User
2019-04-17T08:14:02+02:00

Closes #862

#### Previous behaviour
Steps to reproduce:

1. Import the ical links
2. Click the link in the description

#### New behaviour
Steps to validate that it works:

1. Import the ical links
2. Click the link in the description

Closes #862 (closed)

Previous behaviour

Steps to reproduce:

1. Import the ical links

2. Click the link in the description

New behaviour

Steps to validate that it works:

1. Import the ical links

2. Click the link in the description