Make 1992/marangon main() return int, not void

Due to the fact that void main() will not work in some systems, of
course.

1992/marangon/marangon.c

@@ -48,7 +48,7 @@ I (;y<6;++y)
 I(x=0;x<6;++x)
 mvwaddch(r,X(y),Y(x),z[x][y]+'0'); Q(0);
 }
-void main()
+int main()
 {
 char *ST();
 i a=0,b=0,c,q,t,s,x,sc=0;