VeraCrypt release docs: Fix incorrect command (refs: #15524)

wiki/src/contribute/release_process/veracrypt.mdwn

@@ -45,7 +45,7 @@ If any of these have a new version in stretch or stretch-security:
 
 1. Download the new source package:
 
-       apt source -t ${NEW_VERSION} ${PACKAGE_NAME}
+       apt source ${PACKAGE_NAME}=${NEW_VERSION}
 
 1. Apply the debdiff on the new version:
        debdiff-apply ${PACKAGE_NAME}_${NEW_VERSION}.dsc tails.diff