fix: version label was broken in the absence of a src/version.txt file

src/GenieExtras.jl

@@ -36,8 +36,8 @@ function footer()
         version = version[1:end-2]
     end
     versionfile = joinpath(@__DIR__, "version.txt")
-    version = if isfile(versionfile)
-        join((version, readchomp(versionfile)), "-")
+    if isfile(versionfile)
+        version = join((version, readchomp(versionfile)), "-")
     end
     tagurl = "https://gitlab.com/dbc-nyx/NyxUI.jl/-/tags"
     Html.footer("NyxUI.jl <a href=\"$tagurl\">v$version</a>")