Remove the -F option from tor-resolve.

It used to mean "Force": it would tell tor-resolve to ask tor to
resolve an address even if it ended with .onion.  But when
AutomapHostsOnResolve was added, automatically refusing to resolve
.onion hosts stopped making sense.  So in 0.2.1.16-rc (commit
298dc95dfd8), we made tor-resolve happy to resolve anything.

The -F option stayed in, though, even though it didn't do anything.
Oddly, it never got documented.

Found while fixing GCC 4.6 "set, unused variable" warnings.

changes/bug3208

@@ -0,0 +1,4 @@
+  o Removed options:
+    - Remove undocumented option "-F" from tor-resolve: it hasn't done
+      anything since 0.2.1.16-rc.
+

src/tools/tor-resolve.c

@@ -319,7 +319,7 @@ main(int argc, char **argv)
 {
   uint32_t sockshost;
   uint16_t socksport = 0, port_option = 0;
-  int isSocks4 = 0, isVerbose = 0, isReverse = 0, force = 0;
+  int isSocks4 = 0, isVerbose = 0, isReverse = 0;
   char **arg;
   int n_args;
   struct in_addr a;
@@ -349,8 +349,6 @@ main(int argc, char **argv)
       isSocks4 = 0;
     else if (!strcmp("-x", arg[0]))
       isReverse = 1;
-    else if (!strcmp("-F", arg[0]))
-      force = 1;
     else if (!strcmp("-p", arg[0])) {
       int p;
       if (n_args < 2) {