when linking against ncurses, also link against tinfo

this doesn't hurt anything on debian but fixes building on some other
systems
fixes: #69

Makefile

@@ -35,7 +35,7 @@ endif
 ifeq ($(DISABLE_INTERACTIVE), yes)
  CFLAGS += -DDISABLE_INTERACTIVE
 else
- LIBS += -lncurses
+ LIBS += -lncurses -ltinfo
 endif
 
 # only disable workaround if zerocopy is disabled in librtlsdr, otherwise expect significantly increased CPU use