JSON API debug lambda returned a dangling reference on Android, fix by
moving the scope of the returned object
What made this a bit tricky to understand was the fact that it happened
only on Android, while the code was formally incorrect for all
platforms, and strangely caused a stack overflow due to two std lib
functions (sentry and flush) calling each other ad infinitum
+#23379 0x603cb2a8 in std::__ndk1::basic_ostream<char, std::__ndk1::char_traits<char> >::flush (this=0x618e92bc) at /opt/android-ndk/sources/cxx-stl/llvm-libc++/include/ostream:949
+#23380 0x603cad08 in std::__ndk1::basic_ostream<char, std::__ndk1::char_traits<char> >::sentry::sentry (this=0x618e9284, __os=...) at /opt/android-ndk/sources/cxx-stl/llvm-libc++/include/ostream:270
+#23381 0x603cb2a8 in std::__ndk1::basic_ostream<char, std::__ndk1::char_traits<char> >::flush (this=0x618e92bc) at /opt/android-ndk/sources/cxx-stl/llvm-libc++/include/ostream:949
+#23382 0x603cad08 in std::__ndk1::basic_ostream<char, std::__ndk1::char_traits<char> >::sentry::sentry (this=0x618e9304, __os=...) at /opt/android-ndk/sources/cxx-stl/llvm-libc++/include/ostream:270
+#23383 0x603caa6c in std::__ndk1::__put_character_sequence<char, std::__ndk1::char_traits<char> > (__os=..., __str=0x61379a60 " user: ", __len=7) at /opt/android-ndk/sources/cxx-stl/llvm-libc++/include/ostream:726
+#23384 0x603caa30 in std::__ndk1::operator<< <std::__ndk1::char_traits<char> > (__os=..., __str=0x61379a60 " user: ") at /opt/android-ndk/sources/cxx-stl/llvm-libc++/include/ostream:869
+#23385 0x60522184 in t_RsLogger<(RsLoggerCategories)5>::operator<< <char [8]> (this=0x618e92bc, val=...) at ../../../../Development/rs-develop/libretroshare/src/util/rsdebug.h:53
+#23386 0x60bbe5ec in JsonApiServer::registerHandler(std::__ndk1::basic_string<char, std::__ndk1::char_traits<char>, std::__ndk1::allocator<char> > const&, std::__ndk1::function<void (std::__ndk1::shared_ptr<restbed::Session>)> const&, bool)::$_259::operator()(std::__ndk1::shared_ptr<restbed::Session>, std::__ndk1::function<void (std::__ndk1::shared_ptr<restbed::Session>)> const&) const (this=0x617d8364, session=..., callback=...) at ../../../../Development/rs-develop/libretroshare/src/jsonapi/jsonapi.cpp:517
