Mapfile parsing of LABEL->ANGLE [mycol] fails

[jimk]

Parsing of Mapfile fails with error when there is a label that gets its angle from a column in the data.

e.g.

...
LABEL
   ANGLE [ANG]
   ...
END

The error is: getSymbol(): Symbol definition error. Parsing error near (ANG):(line 73)

This looks like it was introduced in r10021. This looks like a simple off by one error on the vararg list call to getSymbol(). A patch is attached.