Fix image logging bug

Sources/Generator/Extensions/URL+Extensions.swift

@@ -56,7 +56,7 @@ extension URL {
         absoluteString.components(separatedBy: "/").forEach { part in
             if part == ".." {
                 if !components.isEmpty {
-                    _ = components.dropLast()
+                    _ = components.popLast()
                 } else {
                     components.append("..")
                 }

Sources/Generator/Processing/GenerationResultsHandler.swift

@@ -338,7 +338,7 @@ final class GenerationResultsHandler {
     }
 
     private func markImageAsMissing(path: String, source: String) {
-        images.missing[source] = path
+        images.missing[path] = source
     }
 
     private func requireImage(at destination: String, generatedFrom source: String, requiredBy path: String, quality: Float, width: Int, height: Int?, alwaysGenerate: Bool) -> NSSize {