title: importing pycurl with libcurl4 raises ImportError
body: <p>I am using Ubuntu 18.04. If I install libcurl4 (instead of libcurl3), when I import pycurl installed with pipenv I get</p>
  
  <pre><code>&gt;&gt;&gt; import pycurl
  Traceback (most recent call last):
  File "&lt;stdin&gt;", line 1, in &lt;module&gt;
  ImportError: /usr/lib/x86_64-linux-gnu/libcurl.so.4: version `CURL_OPENSSL_3' not found (required by /home/pietro/envs/try_fabric-kcbGLH3z/lib/python3.6/site-packages/pycurl.cpython-36m-x86_64-linux-gnu.so)
  </code></pre>
  
  <p>Note that this error is raised only when I use a pycurl installed with pipenv or pip. If I use instead pycurl installed through apt on system python there are any errors...</p>
  
  <p>What can I do to avoid this impasse?</p>