tool_hugehelp: partially reverted 24e22e10

Compilation was not possible if manuel is disabled due this error:
 error: macro "hugehelp" passed 1 arguments, but takes just 0
  void hugehelp(void) {}

src/tool_hugehelp.h

@@ -23,10 +23,6 @@
  ***************************************************************************/
 #include "tool_setup.h"
 
-#ifdef USE_MANUAL
 void hugehelp(void);
-#else
-#define hugehelp() Curl_nop_stmt
-#endif
 
 #endif /* HEADER_CURL_TOOL_HUGEHELP_H */