fix skill window update

invoke winMgr->updateSkillArea() in mechanicsmanagerimp.cpp after looping
over ESM::Skill::SkillEnum if any updates have occurred.

apps/openmw/mwmechanics/mechanicsmanagerimp.cpp

@@ -338,16 +338,19 @@ namespace MWMechanics
                 }
             }
 
+            bool updateSkills = false;
             //Loop over ESM::Skill::SkillEnum
             for(int i = 0; i < ESM::Skill::Length; ++i)
             {
                 if(stats.getSkill(i) != mWatchedSkills[i] || mWatchedStatsEmpty)
                 {
+                  updateSkills = true;
                     mWatchedSkills[i] = stats.getSkill(i);
                     winMgr->setValue((ESM::Skill::SkillEnum)i, stats.getSkill(i));
                 }
             }
 
+            if (updateSkills) { winMgr->updateSkillArea(); }
             winMgr->setValue("level", stats.getLevel());
 
             mWatchedStatsEmpty = false;