Fix default error logfile

Don't use stderr for error logfile if primary logfile is not stdout
(i.e. always use the same file).

Fix non-colorized duration in DeveolpmentLogger - use std.fmt.fmtDurationSigned.

src/jetzig/Environment.zig

@@ -120,7 +120,10 @@ fn getLogFile(stream: enum { stdout, stderr }, options: Options) !std.fs.File {
 
     if (std.mem.eql(u8, path, "-")) return switch (stream) {
         .stdout => std.io.getStdOut(),
-        .stderr => std.io.getStdErr(),
+        .stderr => if (std.mem.eql(u8, options.log, "-"))
+            std.io.getStdErr()
+        else
+            try std.fs.createFileAbsolute(options.log, .{ .truncate = false }),
     };
 
     const file = try std.fs.createFileAbsolute(path, .{ .truncate = false });

src/jetzig/loggers/DevelopmentLogger.zig

@@ -68,7 +68,11 @@ pub fn logRequest(self: DevelopmentLogger, request: *const jetzig.http.Request)
     const formatted_duration = if (self.stdout_colorized)
         try jetzig.colors.duration(self.allocator, jetzig.util.duration(request.start_time))
     else
-        try std.fmt.allocPrint(self.allocator, "{}", .{jetzig.util.duration(request.start_time)});
+        try std.fmt.allocPrint(
+            self.allocator,
+            "{}",
+            .{std.fmt.fmtDurationSigned(jetzig.util.duration(request.start_time))},
+        );
     defer self.allocator.free(formatted_duration);
 
     const status: jetzig.http.status_codes.TaggedStatusCode = switch (request.response.status_code) {