Fix Kubectl 1.18 version in version map (#1846)

Signed-off-by: Lauri Nevala <lauri.nevala@gmail.com>

src/main/kubectl.ts

@@ -24,7 +24,7 @@ const kubectlMap: Map<string, string> = new Map([
   ["1.15", "1.15.11"],
   ["1.16", "1.16.15"],
   ["1.17", bundledVersion],
-  ["1.18", "1.18.15"],
+  ["1.18", "1.18.14"],
   ["1.19", "1.19.5"],
   ["1.20", "1.20.0"]
 ]);