[LTM] Give "salt lake" visual treatment to Nalsarovar lake in Gujarat

[zijistark]

@Leybrook, make the changes to the SWMH-BETA repository's master branch first, and then follow suit with the adjustments in LTM.

[zijistark]

Scratch that, make the change in the SWMH-BETA develop branch. Forgot that it's a bit harder to auto-merge a bitmap (normally, it would be merged from master -> develop later, but not in this case). 😛