[pca] New patch fails to install because the patchfile is not a patchfile

[Martin Paul]

Hi,

> Can PCA not check the downloaded file is a zip file?

Thanks for the report - I've added an appropriate check to the 
development version of PCA.

Actually PCA alreadys does extensive checking of all possible replies 
from the Oracle server, but that's a moving target. In that case it's 
especially weird: PCA asks the server explicitely for a ZIP file, and 
the server returns an HTML file instead of an appropriate HTTP error code.

Martin.