Increase field flow branch limit.

I'm a little concerned that this appears to be necassary for tests; as it may mean that results involving these flow steps may not be found in real-world projects.

java/ql/test/library-tests/frameworks/guava/generated/test.ql

@@ -39,6 +39,8 @@ class ValueFlowConf extends DataFlow::Configuration {
   override predicate isSink(DataFlow::Node n) {
     n.asExpr().(Argument).getCall().getCallee().hasName("sink")
   }
+
+  override int fieldFlowBranchLimit() { result = 10 }
 }
 
 class TaintFlowConf extends TaintTracking::Configuration {