Re-enable the 'hardcopy' command

Fixes support-requests #53 by Paolo M.

src/frontend/com_hardcopy.c

@@ -23,12 +23,6 @@
  * it doesn't.  */
 void com_hardcopy(wordlist *wl)
 {
-    /* Check if there is a graph available */
-    if (currentgraph == (GRAPH *) NULL) {
-        (void) fprintf(cp_err, "There is no graph to hardcopy.\n");
-        return;
-    }
-
     char *fname;
     size_t n_byte_fname; /* size of fname in bytes, including null */
     char buf[BSIZE_SP], device[BSIZE_SP];