Remove extra new lines for result of EXPLAIN statement

[yfuruyama]

I found EXPLAIN statement shows extra new lines like this:

spanner> explain select 1;             
+-------------------------------------+
| Query_Execution_Plan (EXPERIMENTAL) |
+-------------------------------------+                                                                                                    
|                                     |                 
| .                                   |
| +- Serialize Result                 |
|     +- Unit Relation                |
|                                     |
+-------------------------------------+
1 rows in set (0.34 sec)

I don't remember why I appended new line for the result, but anyway now I removed those new lines so it can align with the result of EXPLAIN ANALYZE statement.

spanner> explain select 1;
+-------------------------------------+
| Query_Execution_Plan (EXPERIMENTAL) |
+-------------------------------------+
| .                                   |
| +- Serialize Result                 |
|     +- Unit Relation                |
+-------------------------------------+
1 rows in set (2.01 sec)

spanner> explain analyze select 1;
+----------------------+---------------+------------+---------------+
| Query_Execution_Plan | Rows_Returned | Executions | Total_Latency |
+----------------------+---------------+------------+---------------+
| .                    |               |            |               |
| +- Serialize Result  | 1             | 1          | 0.01 msecs    |
|     +- Unit Relation | 1             | 1          | 0 msecs       |
+----------------------+---------------+------------+---------------+
1 rows in set (2.8 msecs)
timestamp: 2020-06-16T20:10:20.939172+09:00
cpu:       1.06 msecs
scanned:   0 rows
optimizer: 2

[apstndb]

LGTM