Merge bitcoin#17654: Unbreak build with Boost 1.72.0

a64e97d wallet: unbreak with boost 1.72 (Jan Beich)

Pull request description:

  Regressed by boostorg/filesystem@9a14c37d6f95. See [error log](http://package22.nyi.freebsd.org/data/113amd64-default-PR241449/2019-11-27_11h48m22s/logs/bitcoin-0.19.0.1.log).
  https://github.com/bitcoin/bitcoin/blob/35eda631ed3bd23d4a41761a85a96f925d4a6337/src/fs.h#L14

ACKs for top commit:
  MarcoFalke:
    ACK a64e97d

Tree-SHA512: 0aad2b8ec211bb81021a2f8cd2059364f949be716ebaf154dd97d5c2f7119f42553892e90e6c375018ff2155b996690c7520374762259778de88014cb531ad3b

Author: laanwj

src/fs.h

@@ -11,7 +11,6 @@
 #include <ext/stdio_filebuf.h>
 #endif
 
-#define BOOST_FILESYSTEM_NO_DEPRECATED
 #include <boost/filesystem.hpp>
 #include <boost/filesystem/fstream.hpp>