Information leakage when sending invalid percentage encoding

[NVolcz]

The server emits a stacktrace when sending an invalid percentage encoded formData POST request.
id=test&name=%&message=test

400 - Bad Request

Bad Request

Internal error information:
object.Exception@../../.dub/packages/vibe-d-0.7.31/vibe-d/source/vibe/textfilter/urlencode.d(180): invalid percent encoding
----------------
??:? pure @safe bool std.exception.enforce!(Exception, bool).enforce(bool, lazy const(char)[], immutable(char)[], ulong) [0x7cab1d]
??:? pure @safe void vibe.textfilter.urlencode.filterURLDecode!(std.array.Appender!(immutable(char)[]).Appender).filterURLDecode(ref std.array.Appender!(immutable(char)[]).Appender, const(char)[], bool) [0x7dc64c]
??:? pure @safe immutable(char)[] vibe.textfilter.urlencode.formDecode!(immutable(char)).formDecode(immutable(char)[]) [0x897953]
??:? void vibe.inet.webform.parseURLEncodedForm(immutable(char)[], ref vibe.utils.dictionarylist.DictionaryList!(immutable(char)[], true, 16uL, false).DictionaryList) [0x885d6d]
??:? bool vibe.inet.webform.parseFormData(ref vibe.utils.dictionarylist.DictionaryList!(immutable(char)[], true, 16uL, false).DictionaryList, ref vibe.utils.dictionarylist.__T14DictionaryListTS4vibe4inet7webform8FilePartVbi1Vmi0Vbi0Z.DictionaryList, immutable(char)[], vibe.core.stream.InputStream, ulong) [0x8856f0]
??:? bool vibe.http.server.handleRequest(vibe.core.stream.Stream, vibe.core.net.TCPConnection, vibe.http.server.HTTPListenInfo, ref vibe.http.server.HTTPServerSettings, ref bool) [0x80aa67]
??:? void vibe.http.server.handleHTTPConnection(vibe.core.net.TCPConnection, vibe.http.server.HTTPListenInfo) [0x808f4f]
??:? void vibe.http.server.listenHTTPPlain(vibe.http.server.HTTPServerSettings).doListen(vibe.http.server.HTTPListenInfo, bool, bool).__lambda4(vibe.core.net.TCPConnection) [0x80884c]
??:? void vibe.core.drivers.libevent2_tcp.ClientTask.execute() [0x8ac16c]
??:? void vibe.core.core.makeTaskFuncInfo!(void delegate()).makeTaskFuncInfo(ref void delegate()).callDelegate(vibe.core.core.TaskFuncInfo*) [0x75256f]
??:? void vibe.core.core.CoreTask.run() [0x84b56e]
??:? void core.thread.Fiber.run() [0x931ae7]
??:? fiber_entryPoint [0x931862]
??:? [0xffffffff]

[s-ludwig]

This (HTTPServerOption.errorStackTraces) should probably be disabled in non-debug builds by default. Arguably, any non-500 error could also probably omit the stack trace altogether.