Fixed checkstyle complains (tabs -> spaces).

Author: fredo994

src/main/java/org/influxdb/impl/InfluxDBImpl.java

@@ -924,7 +924,7 @@ public void dropRetentionPolicy(final String rpName, final String database) {
   private String getDatabase(final Query query) {
   	String db = query.getDatabase();
   	if (db == null) {
-  		return this.database;
+  	    return this.database;
 	}
   	return db;
   }