cid#1695402: 'Constant' variable guards dead code

Change-Id: I2be2bce70075386eeac1e5c06450c99e8118009f
Reviewed-on: https://gerrit.libreoffice.org/c/core/+/207339
Tested-by: Jenkins
Reviewed-by: Xisco Fauli <xiscofauli@libreoffice.org>

sd/source/core/sdpage.cxx

@@ -2714,9 +2714,9 @@ OUString SdPage::GetPresObjText(PresObjKind eObjKind) const
     OUString aString;
 
 #if defined(IOS) || defined(ANDROID)
-    bool isMobileDevice = true;
+    const bool isMobileDevice = true;
 #else
-    bool isMobileDevice = false;
+    const bool isMobileDevice = false;
 #endif
 
     if (eObjKind == PresObjKind::Title)