depends: build bdb with -std=c++17

depends/packages/bdb.mk

@@ -11,7 +11,7 @@ $(package)_config_opts=--disable-shared --enable-cxx --disable-replication --ena
 $(package)_config_opts_mingw32=--enable-mingw
 $(package)_config_opts_linux=--with-pic
 $(package)_cflags+=-Wno-error=implicit-function-declaration
-$(package)_cxxflags=-std=c++11
+$(package)_cxxflags=-std=c++17
 $(package)_cppflags_mingw32=-DUNICODE -D_UNICODE
 endef