fix: fix proxy config conditions

Merge branch 'conditional' of https://github.com/gregfaust/ansible-apt into develop

closes #11

templates/etc/apt/apt.conf.d/00proxy.j2

@@ -1,11 +1,11 @@
 // {{ ansible_managed }}
 
-{% if apt_http_proxy_address is defined and not apt_http_proxy_address %}
+{% if apt_http_proxy_address is defined and apt_http_proxy_address %}
 Acquire::http::Proxy "{{ apt_http_proxy_address }}";
 {% endif %}
-{% if apt_https_proxy_address is defined and not apt_https_proxy_address %}
+{% if apt_https_proxy_address is defined and apt_https_proxy_address %}
 Acquire::https::Proxy "{{ apt_https_proxy_address }}";
 {% endif %}
-{% if apt_http_pipeline_depth is defined and not apt_http_pipeline_depth %}
+{% if apt_http_pipeline_depth is defined and apt_http_pipeline_depth %}
 Acquire::http::Pipeline-Depth "{{ apt_http_pipeline_depth }}";
-{% endif %}
+{% endif %}