[SQLLINE-270] Remove maven-compiler-plugin from pom.xml

This solves the same problem as [SQLLINE-273], namely javadoc failure
on JDK 11. I figure it can't hurt to have both solutions.

The fix is derived from [CALCITE-2836]; thanks @risdenk!

pom.xml

@@ -250,14 +250,6 @@
  </execution>
  </executions>
  </plugin>
- <plugin>
- <artifactId>maven-compiler-plugin</artifactId>
- <configuration>
- <source>${maven.compiler.source}</source>
- <target>${maven.compiler.target}</target>
- <compilerArgument>-Xlint:deprecation</compilerArgument>
- </configuration>
- </plugin>
  <plugin>
  <groupId>org.apache.maven.plugins</groupId>
  <artifactId>maven-surefire-plugin</artifactId>