fix(amule): refresh stale --enable-webserver build hint in amuleweb-launch failure (#864) - #866

…aunch failure (amule-project#864)

The user-facing modal that fires when the "Run web server on
startup" preference is enabled but amuleweb cannot be exec'd
suggested the autotools build recipe:

  ...or compile aMule using --enable-webserver and run make install

aMule has moved to CMake; the source-build half of that hint
should now read:

  ...or build aMule from source with -DBUILD_WEBSERVER=YES and
  install it.

Updated src/amule.cpp and po/amule.pot only. po/*.po will be
refreshed on the next routine update-po.sh sweep; translators
will pick up the fuzzy entry then. Localized installs render
the English source string for this one message in the
intervening window — same fallback they would get if msgmerge
were run today (msgfmt skips fuzzy entries from .mo).

Reported by @cardpuncher in amule-project#864.

… pages (amule-project#864)

Stoatwblr's grep on amule-project#864 turned up two more sites carrying the same
autotools-era hint as the amuleweb-launch failure that the previous
commit refreshed:

  - src/webserver/src/WebServer.cpp:2008
    The inline "missing template" error page emitted by amuleweb when
    the configured templates directory is empty/wrong. The hint told
    source builders to run `make` + `make install`.
  - src/webserver/src/missing-template.html:14
    The standalone HTML version of the same error, used when amuleweb
    can find the templates dir but the specific template file is
    missing. Same stale `make install` text.

Replace the autotools commands with the CMake equivalents
(`cmake --build build`, `cmake --install build`) so the help text
matches what a contemporary source build actually looks like.

Both strings are raw HTML string literals -- not `_()`-wrapped --
so they don't appear in the gettext catalog and no `.po` /
`.pot` regeneration is needed.