Missing header for log4cpp

[AdamWill]

I'm just updating the Fedora pion package. It currently uses log4cpp as the logger. As log4cplus is recommended I'll switch to that, but I noticed we have a patch for log4cpp which looks like it's still appropriate for upstream. It adds one more header to logger.hpp:

--- pion-2b16caeedc9b0ffd275867b157305c333c0f118d/include/pion/logger.hpp   2014-10-17 12:42:29.000000000 -0700
+++ pion-2b16caeedc9b0ffd275867b157305c333c0f118d/include/pion/logger.hpp.new   2015-07-28 13:26:49.646424141 -0700
@@ -165,6 +165,7 @@
     #include <log4cpp/BasicLayout.hh>
     #include <log4cpp/OstreamAppender.hh>
     #include <log4cpp/AppenderSkeleton.hh>
+    #include <log4cpp/PropertyConfigurator.hh>

     namespace pion {
         typedef log4cpp::Category*  logger;

As this line comes almost immediately after:

#define PION_LOG_CONFIG(FILE) log4cxx::PropertyConfigurator::configure(FILE);

it sure looks like it's still needed.