auto print new line

gdbgui version:0.13.1.1
web browser: Chrome 68.0.3440.106
system: Ubuntu 16.04
See the program below:

14 | int main()
-- | --
15 | { |  
16 | int b;
17 | printf("%x\n", &b);
18 | printf("%d\n", b);
19 | return 0;
20 | }

I set breakpoint at line 17 and line 18. And just press contine after running the program, then the output below:
```
Breakpoint 1, main (argc=1, argv=0x7fffffffdf68) at test.c:15

15 {

Breakpoint 2, main (argc=1, argv=0x7fffffffdf68) at test.c:17

17 printf("%x\
", &b);

Breakpoint 3, main (argc=1, argv=0x7fffffffdf68) at test.c:18

18 printf("%d\
", b);

ffffde74

32767

[Inferior 1 (process 27154) exited normally]
```

Obviously, gdbgui can not print `\n` properly.