createdb: Fix quoting of --encoding, --lc-ctype and --lc-collate
The original coding failed to properly quote those arguments, leading to
failures when using quotes in the values used. As the quoting can be
encoding-sensitive, the connection to the backend needs to be taken
before applying the correct quoting.
Author: Michael Paquier
Reviewed-by: Daniel Gustafsson
Discussion: https://postgr.es/m/
20200214041004.GB1998@paquier.xyz
Backpatch-through: 9.5