history: Fix missing months for users registered on the 29th/30th/31st

				% my $link_to = $since->strftime('%Y/%m');

				% my $class = $link_to eq $ref ? 'active' : 'waves-effect';

				<li class="<%= $class %>"><a href="/history/<%= $link_to %>"><%= $since->strftime('%m.%Y') %></a></li>

				% $since->add(months => 1);

				% $since->add(months => 1)->set(day => 1, hour => 0, minute => 0, second => 0);

			% }

			<!--<li class="disabled"><a href="#!"><i class="material-icons">chevron_right</i></a></li>-->

		</ul>