Adding "immutability" to the spell check in JDT

Adding immutability as this word is used more frequently in the
programming world.

Change-Id: Ic80927d89ecfa1c2adb1339591ae39ee4ffe7357
Signed-off-by: Lars Vogel <Lars.Vogel@vogella.com>
diff --git a/org.eclipse.jdt.ui/dictionaries/en_GB.dictionary b/org.eclipse.jdt.ui/dictionaries/en_GB.dictionary
index f275815..b878e91 100644
--- a/org.eclipse.jdt.ui/dictionaries/en_GB.dictionary
+++ b/org.eclipse.jdt.ui/dictionaries/en_GB.dictionary
@@ -21916,6 +21916,7 @@
 immunity
 immunity's
 immunology
+immutability
 immutable
 immutableness
 imp
diff --git a/org.eclipse.jdt.ui/dictionaries/en_US.dictionary b/org.eclipse.jdt.ui/dictionaries/en_US.dictionary
index dd8bf20..335f3b3 100644
--- a/org.eclipse.jdt.ui/dictionaries/en_US.dictionary
+++ b/org.eclipse.jdt.ui/dictionaries/en_US.dictionary
@@ -21915,6 +21915,7 @@
 immunity
 immunity's
 immunology
+immutability
 immutable
 immutableness
 imp