vcl: adapt README to VCL_DEBUG_DISABLE_PDFCOMPRESSION changes

No longer need to compile with dbglevel=3 since
4dfa3161

Change-Id: I2dbc7ccd07abd191701c93534241ffd4dfef9df1

vcl/README

@@ -189,13 +189,11 @@ On-screen display differs in step 1 and 2:
 
 === Debugging PDF export ===
 
-Debugging the PDF export becomes much easier in higher debug-levels, where
+Debugging the PDF export becomes much easier when
 compression is disabled (so the PDF file is directly readable) and
 the MARK function puts comments into the PDF file about which method
 generated the following PDF content.
 
-touch vcl/source/gdi/pdfwriter* && make vcl dbglevel=3
-
 The compression can be disabled even using a env. var:
 
 export VCL_DEBUG_DISABLE_PDFCOMPRESSION=1