when print record format by lager:pr which has binary value, need space after '='

[yidayoung]

when print a record like #rec{field =<<"">>}, it will trans to string "#rec{field=<<"">>}" every thing works fine, but when paste this string to shell will cause syntax error before: '=<' because need space after '=' like this "#rec{field= <<"">>}"

so, can we change this format here

https://github.com/erlang-lager/lager/blob/459a3b2cdd9eadd29e5a7ce5c43932f5ccd6eb88/src/lager_trunc_io.erl#L501-L504

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one way is change binary print function

https://github.com/erlang-lager/lager/blob/459a3b2cdd9eadd29e5a7ce5c43932f5ccd6eb88/src/lager_trunc_io.erl#L130-L148 but this may cause some other behavior changed

or just add ensure_space after print function, like this

    {FieldStr, FieldLen} = print(Field, Max - ExtraChars, Options),
    {ValueStr, ValueLen} = print(Value, Max - (FieldLen + ExtraChars), Options),
    {ValueStr2, ValueLen2} = ensure_space(Value, ValueStr, ValueLen),
    {Final, FLen} = record_fields(T, Max - (FieldLen + ValueLen + ExtraChars), dec_depth(Options)),
    {[FieldStr++"="++ValueStr2++Terminator|Final], FLen + FieldLen + ValueLen2 + ExtraChars}.

ensure_space(Value, ValueStr, ValueLen) when is_binary(Value) ->
    {" "+ValueStr, ValueLen+1};
ensure_space(_Value, ValueStr, ValueLen) ->
    {ValueStr, ValueLen}.

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if add ensure_space is enough, i can make a pr for this