Adjust path in javadoc.sh

Valid module for 4.x is "core" and not "driver-core".
Wrong path leads to script failing on `mv` step.

(cherry picked from commit 351fb9a60b68addf7a2540acefcdf70270dc5ba3)

Author: Bouncheck

docs/_utils/javadoc.sh

@@ -14,4 +14,4 @@ fi
 mvn javadoc:javadoc -T 1C
 [ -d $OUTPUT_DIR ] && rm -r $OUTPUT_DIR
 mkdir -p "$OUTPUT_DIR"
-mv -f driver-core/target/site/apidocs/* $OUTPUT_DIR
+mv -f core/target/site/apidocs/* $OUTPUT_DIR