Fixed a bug in load_libsvm_formatted_data(). Forgot to clear the contents

of the labels output vector before adding the loaded label data.

--HG--
extra : convert_revision : svn%3Afdd8eb12-d10e-0410-9acb-85c331704f74/trunk%404161

dlib/data_io/libsvm_io.h

@@ -45,6 +45,7 @@ namespace dlib
         COMPILE_TIME_ASSERT(is_unsigned_type<key_type>::value);
 
         samples.clear();
+        labels.clear();
 
         ifstream fin(file_name.c_str());