Revert Guava 20 features until we get the build working properly

*** Original change description ***

Remove deprecated methods with Guava 20 release

***

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=137945126

javatests/google/registry/server/UrlChecker.java

@@ -45,8 +45,7 @@ final class UrlChecker {
         }
       }, timeoutMs, TimeUnit.MILLISECONDS, true);
     } catch (Exception e) {
-      Throwables.throwIfUnchecked(e);
-      throw new RuntimeException(e);
+      throw Throwables.propagate(e);
     }
   }