app/internal/window,app/internal/xkb: silence string(int) conversion warnings

Signed-off-by: Elias Naur <mail@eliasnaur.com>

app/internal/window/os_windows.go

@@ -470,7 +470,7 @@ func (w *window) HWND() (syscall.Handle, int, int) {
 
 func convertKeyCode(code uintptr) (string, bool) {
 	if '0' <= code && code <= '9' || 'A' <= code && code <= 'Z' {
-		return string(code), true
+		return string(rune(code)), true
 	}
 	var r string
 	switch code {

app/internal/xkb/xkb_unix.go

@@ -228,10 +228,10 @@ func (x *Context) UpdateMask(depressed, latched, locked, depressedGroup, latched
 
 func convertKeysym(s C.xkb_keysym_t) (string, bool) {
 	if 'a' <= s && s <= 'z' {
-		return string(s - 'a' + 'A'), true
+		return string(rune(s - 'a' + 'A')), true
 	}
 	if ' ' <= s && s <= '~' {
-		return string(s), true
+		return string(rune(s)), true
 	}
 	var n string
 	switch s {