Fix stupid change

Dependencies

• [2] 6XSBP2VG Whitespace
• [3] 6U6KBFYP Build the HTML manual; add the HTML & PDF to the distribution; install them.
• [4] FV2M6MOT hydra: use autoconf/-make

Change contents

• replacement in doc/manual/Makefile.am at line 33
  [3.811]→[2.30:79](∅→∅)
  − $(DBLATEX) $(dblatex_opts) manual.xml \
  [3.811]

  [3.17245]
  + $(DBLATEX) $(dblatex_opts) manual.xml; \