Move ratio calcation of read API to avoid NPE with useReadAPI(false)

If a query takes longer than 10+ seconds, the returned job will not have results / totalRows
thus totalRows will be null,
However, if useReadAPI is false the moved line would throw a null pointer exception trying to unbox
the (nullable -- and actually null) Long for division.

google-cloud-bigquery/src/main/java/com/google/cloud/bigquery/ConnectionImpl.java

@@ -1217,8 +1217,8 @@ boolean useReadAPI(Long totalRows, Long pageRows, Schema schema, Boolean hasQuer
       return false;
     }
 
-    long resultRatio = totalRows / pageRows;
     if (Boolean.TRUE.equals(connectionSettings.getUseReadAPI())) {
+      long resultRatio = totalRows / pageRows;
       return resultRatio >= connectionSettings.getTotalToPageRowCountRatio()
           && totalRows > connectionSettings.getMinResultSize();
     } else {