Bug 21356: Add Missing space in parcel.tt

Bug 21356: Add Missing space in parcel.tt

This patch adds a space between the user's name and 'On:'
in parcel.tt.

To test:

1) Go to Acquisitions
2) Search for a vendor
3) Create a new basket
4) Add an order to the basket
5) Close the basket
6) Receive the order
7) In the page title 'Receipt summary' notice there is no space
between the 'Received by' user name and 'On:'
8) Apply the patch
9) Refresh the page, there should now be a space

Signed-off-by: Fridolin Somers <fridolin.somers@biblibre.com>
Signed-off-by: Jonathan Druart <jonathan.druart@bugs.koha-community.org>
Signed-off-by: Nick Clemens <nick@bywatersolutions.com>