Fixed bad const-cast.

src/common/plugin.c

@@ -970,6 +970,7 @@ hexchat_printf (hexchat_plugin *ph, const char *format, ...)
 void
 hexchat_command (hexchat_plugin *ph, const char *command)
 {
+	char *command_nonconst;
 	char *conv;
 	gssize len = -1;
 
@@ -980,9 +981,11 @@ hexchat_command (hexchat_plugin *ph, const char *command)
 	}
 
 	/* scripts/plugins continue to send non-UTF8... *sigh* */
-	conv = text_validate ((char **)&command, &len);
-	handle_command (ph->context, (char *)command, FALSE);
+	command_nonconst = g_strdup (command);
+	conv = text_validate (&command_nonconst, &len);
+	handle_command (ph->context, command_nonconst, FALSE);
 	g_free (conv);
+	g_free (command_nonconst);
 }
 
 void