Set level back to verbose - messages are too annoying as it is common

to attempt to load property files which don't exist - there for optional
override of properties.

PR:	1451


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@269329 13f79535-47bb-0310-9956-ffa450edef68

src/main/org/apache/tools/ant/taskdefs/Property.java

@@ -199,7 +199,7 @@ public class Property extends Task {
                 addProperties(props);
             } else {
                 log("Unable to find property file: " + file.getAbsolutePath(), 
-                    Project.MSG_WARN);
+                    Project.MSG_VERBOSE);
             }
         } catch(Exception ex) {
             throw new BuildException(ex.getMessage(), ex, location);