fix: replace unsafe call of non-nullable symbol

With a takIf/let pattern. Theoretically you can have two threads
racing - one changing the value of lastDeploymentURL and another
\one reading. In our code that should be pretty much impossible.
But the compiler can't be sure of that so it throws and error.

Author: fioan89

src/main/kotlin/com/coder/toolbox/CoderToolboxContext.kt

@@ -42,12 +42,9 @@ data class CoderToolboxContext(
      */
     val deploymentUrl: URL
         get() {
-            if (!this.settingsStore.lastDeploymentURL.isNullOrBlank()) {
-                return this.settingsStore.lastDeploymentURL!!.toURL()
-            } else if (this.secrets.lastDeploymentURL.isNotBlank()) {
-                return this.secrets.lastDeploymentURL.toURL()
-            }
-            return this.settingsStore.defaultURL.toURL()
+            return settingsStore.lastDeploymentURL?.takeIf { it.isNotBlank() }?.toURL()
+                ?: secrets.lastDeploymentURL.takeIf { it.isNotBlank() }?.toURL()
+                ?: settingsStore.defaultURL.toURL()
         }
 
     suspend fun logAndShowError(title: String, error: String) {