fix module install rule (man pages in `docs` directory)

git-svn-id: https://svn.osgeo.org/grass/grass/trunk@52332 15284696-431f-4ddb-bdfa-cd5b030d7da7

include/Make/Module.make

@@ -18,6 +18,6 @@ $(BIN)/$(PGM)$(EXE): $(ARCH_OBJS) $(DEPENDENCIES)
 install:
 	$(INSTALL) $(ARCH_DISTDIR)/bin/$(PGM)$(EXE) $(INST_DIR)/bin/
 	$(INSTALL_DATA) $(HTMLDIR)/$(PGM).html $(INST_DIR)/docs/html/
-	$(INSTALL_DATA) $(ARCH_DISTDIR)/man/man1/$(PGM).1 $(INST_DIR)/man/man1/
+	$(INSTALL_DATA) $(ARCH_DISTDIR)/docs/man/man1/$(PGM).1 $(INST_DIR)/docs/man/man1/
 
 .PHONY: cmd