Fixed typo in SDL_clipboard.h

include/SDL3/SDL_clipboard.h

@@ -59,7 +59,7 @@ extern SDL_DECLSPEC bool SDLCALL SDL_SetClipboardText(const char *text);
 /**
  * Get UTF-8 text from the clipboard.
  *
- * This functions returns empty string if there was not enough memory left for
+ * This functions returns an empty string if there was not enough memory left for
  * a copy of the clipboard's content.
  *
  * \returns the clipboard text on success or an empty string on failure; call
@@ -102,7 +102,7 @@ extern SDL_DECLSPEC bool SDLCALL SDL_SetPrimarySelectionText(const char *text);
 /**
  * Get UTF-8 text from the primary selection.
  *
- * This functions returns empty string if there was not enough memory left for
+ * This functions returns an empty string if there was not enough memory left for
  * a copy of the primary selection's content.
  *
  * \returns the primary selection text on success or an empty string on