Fix attempts to place enemy/plat bounds & scripts with bad corner order

There is a certain ordering of which corners you click on to place enemy
and platform boundaries, and script boxes. You must first click on the
top-left corner, then click on the bottom-right corner. The visual box
that is drawn after you've first clicked on the top-left corner clearly
shows this intended way of doing things.

However, it seems like despite the visuals, the game didn't properly
prevent you from clicking on the corners in the wrong way. If you placed
it from top-right to bottom-left, or bottom-left to top-right, then the
game would place the boxes accordingly, and they would have a weird
shape where two of its opposite sides would just be missing. But,
placing them from bottom-right to top-left is prevented accordingly.

The bug comes down to a simple use of "or", instead of the correct
"and". This isn't the first time the wrong conjunction was used in a
conditional... (8260bb2696, #136)

Since the code block that the if-statement guards is the code that will
execute if the corners placed were correct, the if-statement thus should
be written in the positive case and use a more restrictive "and",
instead of the negative case, which would use a more looser "or". There
are less cases that are correct than cases which are incorrect - in this
case, there is only 1 correct way of doing things (top-left to
bottom-right), compared to 3 incorrect ways of doing things (top-right
to bottom-left, bottom-left to top-right, bottom-right to top-left) - so
when thinking of positive cases, you should be using "and".

Or, you can always just test it. This bug has been in the game since
2.0, so it seems like no one just tested that incorrect input actually
didn't work.

desktop_version/src/editor.cpp

@@ -4745,7 +4745,7 @@ void editorinput()
                         }
                         else if(ed.boundarymod==2)
                         {
-                            if((ed.tilex*8)+8>=ed.boundx1 || (ed.tiley*8)+8>=ed.boundy1)
+                            if((ed.tilex*8)+8>=ed.boundx1 && (ed.tiley*8)+8>=ed.boundy1)
                             {
                                 ed.boundx2=(ed.tilex*8)+8;
                                 ed.boundy2=(ed.tiley*8)+8;