Small fix for Debian installations

[rudybroersma]

The package installation on Debian does not work, because the package 'Pound' does not exists. It is called 'pound' (lowercase p).

The result of the current version is:

Error: Execution of '/usr/bin/apt-get -q -y -o DPkg::Options::=--force-confold install Pound' returned 100: Reading package lists...
Building dependency tree...
Reading state information...
E: Unable to locate package Pound
Error: /Stage[main]/Pound::Install/Package[pound]/ensure: change from purged to present failed: Execution of '/usr/bin/apt-get -q -y -o DPkg::Options::=--force-confold install Pound' returned 100: Reading package lists...
Building dependency tree...
Reading state information...
E: Unable to locate package Pound

This can be verified manually:

# /usr/bin/apt-get -q -y -o DPkg::Options::=--force-confold install Pound
Reading package lists...
Building dependency tree...
Reading state information...
E: Unable to locate package Pound

While lowercase does work:

# /usr/bin/apt-get -q -y -o DPkg::Options::=--force-confold install pound
Reading package lists...
Building dependency tree...
Reading state information...
The following NEW packages will be installed:
  pound
0 upgraded, 1 newly installed, 0 to remove and 0 not upgraded.
Need to get 108 kB of archives.
After this operation, 212 kB of additional disk space will be used.
Get:1 http://mirror.duocast.net/debian stretch/main amd64 pound amd64 2.7-1.3 [108 kB]
Fetched 108 kB in 0s (2,964 kB/s)
Selecting previously unselected package pound.
(Reading database ... 42731 files and directories currently installed.)
Preparing to unpack .../pound_2.7-1.3_amd64.deb ...
Unpacking pound (2.7-1.3) ...
Processing triggers for systemd (232-25+deb9u1) ...
Processing triggers for man-db (2.7.6.1-2) ...
Setting up pound (2.7-1.3) ...
Processing triggers for systemd (232-25+deb9u1) ...