[nullsafe] Remove a wrong model for com.google.common.collect.Iterables.getFirst()

Summary:
1. The return value is annotated as Nullable in codebase
2. The second parameter can be null as well.

Reviewed By: artempyanykh

Differential Revision: D20766243

fbshipit-source-id: 9aad37a8c

infer/src/nullsafe/modelTables.ml

@@ -426,9 +426,6 @@ let annotated_list_nullability_other =
   ; ( o1
     , "com.google.common.collect.ImmutableMap.copyOf(java.lang.Iterable):com.google.common.collect.ImmutableMap"
     )
-  ; ( on
-    , "com.google.common.collect.Iterables.getFirst(java.lang.Iterable,java.lang.Object):java.lang.Object"
-    )
   ; ( o1
     , "com.google.common.util.concurrent.SettableFuture.setException(java.lang.Throwable):boolean"
     )