Revert "Relax ICC profile version for PDF/1-a to 2.4"

The lcms2 author advises 2.1 and that is the version we advertize
in the name of the embedded icc file.

This reverts commit 3bb22684.

vcl/source/gdi/pdfwriter_impl.cxx

@@ -6563,8 +6563,8 @@ sal_Int32 PDFWriterImpl::emitOutputIntent()
     beginCompression();
     checkAndEnableStreamEncryption( nICCObject );
     cmsHPROFILE hProfile = cmsCreate_sRGBProfile();
-//force ICC profile version 2.4
-    cmsSetProfileVersion(hProfile, 2.4);
+//force ICC profile version 2.1
+    cmsSetProfileVersion(hProfile, 2.1);
     cmsUInt32Number nBytesNeeded = 0;
     cmsSaveProfileToMem(hProfile, NULL, &nBytesNeeded);
     if (!nBytesNeeded)