RFR: 8324237: Typo in comment in GlassApplication.m

[Kevin Rushforth]

Simple fix of a typo in a code comment.

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Commit messages:
 - 8324237: Typo in comment in GlassApplication.m

Changes: https://git.openjdk.org/jfx/pull/1343/files
 Webrev: https://webrevs.openjdk.org/?repo=jfx&pr=1343&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8324237
  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/jfx/pull/1343.diff
  Fetch: git fetch https://git.openjdk.org/jfx.git pull/1343/head:pull/1343

PR: https://git.openjdk.org/jfx/pull/1343