apkbuild-gem-resolver: fix -u option

overlapping variable names

apkbuild-gem-resolver.in

@@ -326,13 +326,13 @@ end
 
 
 testing = false
-update = false
+update_files = false
 OptionParser.new do |opts|
   opts.on('-t', '--testing') do |t|
     testing = t
   end
   opts.on('-u', '--update') do |u|
-    update = u
+    update_files = u
   end
 end.parse! ARGV
 Package.initialize testing
@@ -360,7 +360,7 @@ for pkg in update
           nil : " (obsolete dependencies: #{obsolete.join ', '})"
   puts "#{pkg[:name]}-#{pkg[:version]}#{obs}"
 
-  if update
+  if update_files
     package = Package.get(pkg[:name])
     package.version = pkg[:version]
     for dep in obsolete
@@ -369,6 +369,6 @@ for pkg in update
   end
 end
 
-if update
+if update_files
   Package.save
 end