Fix typo

core/src/main/java/hudson/model/RunMap.java

@@ -186,7 +186,7 @@ public final class RunMap<R extends Run<?,R>> extends AbstractLazyLoadRunMap<R>
         // Defense against JENKINS-23152 and its ilk.
         File rootDir = r.getRootDir();
         if (rootDir.isDirectory()) {
-            throw new IllegalStateException(rootDir + " already existed; will not overwite with " + r);
+            throw new IllegalStateException(rootDir + " already existed; will not overwrite with " + r);
         }
         if (!r.getClass().getName().equals("hudson.matrix.MatrixRun")) { // JENKINS-26739: grandfathered in
             proposeNewNumber(r.getNumber());