[client] Standardize on two spaces for whitespace in Client.java.
[client] Standardize on two spaces for whitespace in Client.java.

cricket007/YCSB,madhurihn/YCSB_ToyDB,jaemyoun/YCSB,ChristianNavolskyi/YCSB,leschekhomann/YCSB,ChristianNavolskyi/YCSB,zyguan/ycsb,zyguan/ycsb,ChristianNavolskyi/YCSB,madhurihn/YCSB_ToyDB,brianfrankcooper/YCSB,brianfrankcooper/YCSB,cricket007/YCSB,madhurihn/YCSB_ToyDB,brianfrankcooper/YCSB,jaemyoun/YCSB,madhurihn/YCSB_ToyDB,jaemyoun/YCSB,manolama/YCSB,cricket007/YCSB,zyguan/ycsb,leschekhomann/YCSB,cricket007/YCSB,leschekhomann/YCSB,manolama/YCSB,zyguan/ycsb,jaemyoun/YCSB,brianfrankcooper/YCSB,leschekhomann/YCSB,manolama/YCSB,ChristianNavolskyi/YCSB,manolama/YCSB