Bug 383564, fix memory leak. Patch by Andrew Gaul, r=mscott, sr=bienvenu.

extensions/spellcheck/myspell/src/myspell.cpp

@@ -38,7 +38,7 @@ MySpell::~MySpell()
     delete pSMgr;
     delete pAMgr;
     delete pHMgr;
-    
+    delete csconv;
     csconv= NULL;
     if (encoding) 
         free(encoding);