Modernize some code

Author: joto

include/osmium/io/pbf.hpp

@@ -47,7 +47,7 @@ namespace osmium {
             std::vector<std::string> types{"none", "zlib"};
 
 #ifdef OSMIUM_WITH_LZ4
-            types.push_back("lz4");
+            types.emplace_back("lz4");
 #endif
 
             return types;

include/osmium/memory/collection.hpp

@@ -137,8 +137,8 @@ namespace osmium {
             using pointer           = value_type*;
             using reference         = value_type&;
 
-            CollectionFilterIterator(const TFilter& filter, CollectionIterator<TMember> begin, CollectionIterator<TMember> end) :
-                m_filter(filter),
+            CollectionFilterIterator(TFilter filter, CollectionIterator<TMember> begin, CollectionIterator<TMember> end) :
+                m_filter(std::move(filter)),
                 m_it(begin),
                 m_end(end) {
                 advance();