Remove a redundant check in ..transition_affects_guards()

scan-build found that we we checking UseEntryGuards twice.

Fixes bug 21492.

changes/bug21492

@@ -0,0 +1,5 @@
+  o Minor bugfixes (correctness):
+    - Remove a redundant check for the UseEntryGuards option from the
+      options_transition_affects_guards() function. Fixes bug 21492;
+      bugfix on 0.3.0.1-alpha.
+

src/or/config.c

@@ -1587,7 +1587,6 @@ options_transition_affects_guards(const or_options_t *old,
   return
     (old->UseEntryGuards != new->UseEntryGuards ||
      old->UseBridges != new->UseBridges ||
-     old->UseEntryGuards != new->UseEntryGuards ||
      old->ClientUseIPv4 != new->ClientUseIPv4 ||
      old->ClientUseIPv6 != new->ClientUseIPv6 ||
      old->FascistFirewall != new->FascistFirewall ||