PDF: revert fix for #4484 (only compress images on last run).

Closes #4755.

This will mean some increase in the time it takes to
produce an image-heavy PDF with xelatex, but it will
make tables of contents correct, which is more important.

Note that the production time should also be decreased
by the previous commit, which fixed a logic error
affecting the number of runs.  That change might mitigate
the effect of this one.

src/Text/Pandoc/PDF.hs

@@ -285,12 +285,7 @@ runTeXProgram verbosity program args runNumber numRuns tmpDir source = do
     let file' = file
 #endif
     let programArgs = ["-halt-on-error", "-interaction", "nonstopmode",
-         "-output-directory", tmpDir'] ++
-         -- see #4484, only compress images on last run:
-         if program == "xelatex" && runNumber < numRuns
-            then ["-output-driver", "xdvipdfmx -z0"]
-            else []
-         ++ args ++ [file']
+         "-output-directory", tmpDir'] ++ args ++ [file']
     env' <- getEnvironment
     let sep = [searchPathSeparator]
     let texinputs = maybe (tmpDir' ++ sep) ((tmpDir' ++ sep) ++)