osm-pbf: revision for protobuf

build with C++11

Formula/osm-pbf.rb

@@ -3,7 +3,7 @@ class OsmPbf < Formula
   homepage "https://wiki.openstreetmap.org/wiki/PBF_Format"
   url "https://github.com/scrosby/OSM-binary/archive/v1.3.3.tar.gz"
   sha256 "a109f338ce6a8438a8faae4627cd08599d0403b8977c185499de5c17b92d0798"
-  revision 4
+  revision 5
 
   bottle do
     cellar :any_skip_relocation
@@ -15,7 +15,11 @@ class OsmPbf < Formula
 
   depends_on "protobuf"
 
+  needs :cxx11
+
   def install
+    ENV.cxx11
+
     cd "src" do
       system "make"
       lib.install "libosmpbf.a"