man page has nroff errors

[djw1149]

nroff on macOS and debian stretch complains when processing the man page.

nroff -man dnsdbq.man 
mdoc warning: Empty input line #40
mdoc warning: Empty input line #48
mdoc warning: Empty input line #85
mdoc warning: Empty input line #99
mdoc warning: Empty input line #111
mdoc warning: Empty input line #206
mdoc warning: Empty input line #224
mdoc warning: Empty input line #234
mdoc warning: Empty input line #291
mdoc warning: Unknown list type `-offset' (or missing list type)
              in .Bl macro

Usage: .Bl {-hang | -ohang | -tag | -diag | -inset}
             [-width <string>]
             [-offset <string>] [-compact]
       .Bl -column [-offset <string>] <string1> <string2> ...
       .Bl {-item | -enum [-nested] | -bullet | -hyphen | -dash}
             [-offset <string>] [-compact] (#292)
mdoc error: .It without preceding .Bl (#293)
mdoc warning: .It macros in lists of type `'
              require arguments (#293)
mdoc error: .It without preceding .Bl (#296)
mdoc warning: .It macros in lists of type `'
              require arguments (#296)
mdoc warning: extraneous .El call (#299)
mdoc warning: extraneous .El call (#300)
mdoc warning: Empty input line #304
mdoc warning: Unknown list type `-offset' (or missing list type)
              in .Bl macro

Usage: .Bl {-hang | -ohang | -tag | -diag | -inset}
             [-width <string>]
             [-offset <string>] [-compact]
       .Bl -column [-offset <string>] <string1> <string2> ...
       .Bl {-item | -enum [-nested] | -bullet | -hyphen | -dash}
             [-offset <string>] [-compact] (#305)
mdoc error: .It without preceding .Bl (#306)
mdoc warning: .It macros in lists of type `'
              require arguments (#306)
mdoc error: .It without preceding .Bl (#309)
mdoc warning: .It macros in lists of type `'
              require arguments (#309)

[vixie]

fixed in 2f3fa8b