Replaced include guards with #pragma onceHEADmaster

Thanks to https://github.com/cgmb/guardonce and a follow-up replace to
remove duplicated newlines at end of file:

    find src -type f -name '*.h' -exec \
      sed --in-place -e :a -e '/^\n*$/{$d;N;};/\n$/ba' {} \;

Source: https://unix.stackexchange.com/questions/81685/how-to-remove-multiple-newlines-at-eof

Fixes compile on macOS, which appears to have been due to the EVENT_H
include guard.

1 files changed, 3 insertions, 4 deletions

diff --git a/src/net/specialhandler.h b/src/net/specialhandler.h
index fb8ffdfd..df09087d 100644
--- a/src/net/specialhandler.h
+++ b/src/net/specialhandler.h
@@ -19,12 +19,12 @@
  *  along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#ifndef SPECIALHANDLER_H
-#define SPECIALHANDLER_H
+#pragma once
 
 #include <iosfwd>
 
 namespace Net {
+
 class SpecialHandler
 {
     public:
@@ -38,6 +38,5 @@ class SpecialHandler
 
         virtual void use(int id, const std::string &map) = 0;
 };
-}
 
-#endif // SPECIALHANDLER_H
+} // namespace Net