Added URHO3D_URHO2D guard that seems omitted

Source/Samples/49_Urho2DIsometricDemo/CMakeLists.txt

@@ -20,6 +20,10 @@
 # THE SOFTWARE.
 #
 
+if (NOT URHO3D_URHO2D)
+    return ()
+endif ()
+
 # Define target name
 set (TARGET_NAME 49_Urho2DIsometricDemo)
 

Source/Samples/50_Urho2DPlatformer/CMakeLists.txt

@@ -20,6 +20,10 @@
 # THE SOFTWARE.
 #
 
+if (NOT URHO3D_URHO2D)
+    return ()
+endif ()
+
 # Define target name
 set (TARGET_NAME 50_Urho2DPlatformer)