Actually put ExtORPortCookieAuthFile into config.c

Fixes bug 11635; bugfix on 0.2.5.1-alpha.

changes/bug11635

@@ -0,0 +1,6 @@
+  o Minor bugfixes (pluggable transports):
+    - Enable the ExtORPortCookieAuthFile option, to allow changing the
+      default location of the authentication token for the extended OR Port
+      as used by sever-side pluggable transports. We had implemented this
+      option before, but the code to make it settable had been omitted.
+      Fixes bug 11635; bugfix on 0.2.5.1-alpha.

src/or/config.c

@@ -237,6 +237,7 @@ static config_var_t option_vars_[] = {
   V(ExitPortStatistics,          BOOL,     "0"),
   V(ExtendAllowPrivateAddresses, BOOL,     "0"),
   VPORT(ExtORPort,               LINELIST, NULL),
+  V(ExtORPortCookieAuthFile,     STRING,   NULL),
   V(ExtraInfoStatistics,         BOOL,     "1"),
   V(FallbackDir,                 LINELIST, NULL),