Always call system commands silently

This prevents annoying messages like "Command terminated" in #13.
We already do custom error handling anyway.

Author: vimpostor

autoload/lumen/platforms/linux.vim

@@ -24,7 +24,7 @@ func lumen#platforms#linux#parse_line(line)
 endfunc
 
 func lumen#platforms#linux#oneshot()
-	let out = trim(system('gdbus call -t 1 --session --dest=org.freedesktop.portal.Desktop --object-path=/org/freedesktop/portal/desktop --method=org.freedesktop.portal.Settings.Read org.freedesktop.appearance color-scheme'))
+	silent let out = trim(system('gdbus call -t 1 --session --dest=org.freedesktop.portal.Desktop --object-path=/org/freedesktop/portal/desktop --method=org.freedesktop.portal.Settings.Read org.freedesktop.appearance color-scheme'))
 	if match(out, "(<<uint32 ") == 0
 		call lumen#platforms#linux#parse_line(s:watched_line . strcharpart(out, 10, 1) . ">)")
 	else

autoload/lumen/platforms/macos.vim

@@ -13,11 +13,11 @@ func lumen#platforms#macos#parse_line(line)
 endfunc
 
 func lumen#platforms#macos#oneshot()
-	let out = get(systemlist(printf("%s get || swiftc %s.swift -o %s", s:exe, s:exe, s:exe)), 0)
+	silent let out = get(systemlist(printf("%s get || swiftc %s.swift -o %s", s:exe, s:exe, s:exe)), 0)
 	if len(out) != 5
 		let err = out
 		" fallback
-		let out = get(systemlist(s:exe . ".swift get"), 0)
+		silent let out = get(systemlist(s:exe . ".swift get"), 0)
 	endif
 
 	if len(out) == 5

autoload/lumen/platforms/windows.vim

@@ -15,7 +15,7 @@ func lumen#platforms#windows#parse_line(line)
 endfunc
 
 func lumen#platforms#windows#oneshot()
-	let out = system('reg.exe query "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Themes\Personalize" /v AppsUseLightTheme')->trim()->split('\r\n')
+	silent let out = system('reg.exe query "HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Themes\Personalize" /v AppsUseLightTheme')->trim()->split('\r\n')
 	if len(out)
 		call lumen#platforms#windows#parse_line(out[-1])
 	endif