Fix overwrite+remove deleting the wrong file on relative path. (#235)

Issue was caused by updater.pathToNewFile() fetching the path directly from zSyncClient, which will keep absolute paths as-is
and change relative paths to be different than the parameter value would be.

Author: EXio4

src/cli/main.cpp

@@ -60,7 +60,9 @@ int main(const int argc, const char** argv) {
 
     optional<string> pathToAppImage = [&args]() {
         if (!args.pos.empty()) {
-            return optional<string>(args.as<string>(0));
+            // calculate absolute path to normalize the path for when it's
+            // checked back from Updater::pathToNewFile
+            return optional<string>(abspath(args.as<string>(0)));
         }
 
         return optional<string>();
@@ -240,6 +242,9 @@ int main(const int argc, const char** argv) {
         return 1;
     }
 
+    // normalize against pathToAppImage - so they follow the same format
+    newFilePath = abspath(newFilePath);
+
     auto validationResult = updater.validateSignature();
 
     while (updater.nextStatusMessage(nextMessage))