Fix files.first to use correct files.exists sig.

Fixes fabric#499.

docs/changelog.rst

@@ -25,6 +25,9 @@ would have also been included in the 1.2 line.
 Changelog
 =========
 
+* :bug:`499` `contrib.files.first <fabric.contrib.files.first>` used an
+  outdated function signature in its wrapped `~fabric.contrib.files.exists`
+  call. This has been fixed. Thanks to Massimiliano Torromeo for catch & patch.
 * :bug:`551` :option:`--list <-l>` output now detects terminal window size
   and truncates (or doesn't truncate) accordingly. Thanks to Horacio G. de Oro
   for the initial pull request.

fabric/contrib/files.py

@@ -38,15 +38,11 @@ def exists(path, use_sudo=False, verbose=False):
 def first(*args, **kwargs):
     """
     Given one or more file paths, returns first one found, or None if none
-    exist. May specify ``use_sudo`` which is passed to `exists`.
+    exist. May specify ``use_sudo`` and ``verbose`` which are passed to `exists`.
     """
     for directory in args:
-        if not kwargs.get('use_sudo'):
-            if exists(directory, sudo=False):
-                return directory
-        else:
-            if exists(directory):
-                return directory
+        if exists(directory, **kwargs):
+            return directory
 
 
 def upload_template(filename, destination, context=None, use_jinja=False,