ignore presence/absence of xsltproc, just use the bundled manuals
which are included in tarball downloads

Index: man/CMakeLists.txt
--- man/CMakeLists.txt.orig
+++ man/CMakeLists.txt
@@ -5,7 +5,7 @@
 # because the install is optional.
 
 find_program(XSLTPROC xsltproc OPTIONAL)
-if(XSLTPROC)
+if(FALSE)
 	function(compile_manpage page)
 		add_custom_command(OUTPUT ${PROJECT_SOURCE_DIR}/man/${page}
 			COMMAND xsltproc ${PROJECT_SOURCE_DIR}/man/${page}.xml -o ${PROJECT_SOURCE_DIR}/man/
@@ -24,7 +24,9 @@ if(XSLTPROC)
 	compile_manpage("mosquitto-tls.7")
 	compile_manpage("mqtt.7")
 	compile_manpage("mosquitto.8")
+endif()
 
+if(TRUE)
 	install(FILES
 		mosquitto_ctrl.1
 		mosquitto_ctrl_dynsec.1