Update management of channel_refresh_interval

Follow indications:
https://github.com/iv-org/invidious/pull/2915#discussion_r811373503

src/invidious/helpers/utils.cr

@@ -53,6 +53,24 @@ def recode_length_seconds(time : Int32) : String
   end
 end
 
+def decode_interval(string : String) : Time::Span
+  rawMinutes = string.try &.to_i32?
+
+  if !rawMinutes
+    hours = /(?<hours>\d+)h/.match(string).try &.["hours"].try &.to_i32
+    hours ||= 0
+
+    minutes = /(?<minutes>\d+)m(?!s)/.match(string).try &.["minutes"].try &.to_i32
+    minutes ||= 0
+
+    time = Time::Span.new(hours: hours, minutes: minutes)
+  else
+    time = Time::Span.new(minutes: rawMinutes)
+  end
+
+  return time
+end
+
 def decode_time(string)
   time = string.try &.to_f?
 

src/invidious/user/preferences.cr

@@ -259,15 +259,15 @@ struct Preferences
 
   module TimeSpanConverter
     def self.to_yaml(value : Time::Span, yaml : YAML::Nodes::Builder)
-      return yaml.scalar recode_length_seconds(value.total_seconds.to_i32)
+      return yaml.scalar value.total_minutes.to_i32
     end
 
     def self.from_yaml(ctx : YAML::ParseContext, node : YAML::Nodes::Node) : Time::Span
       if node.is_a?(YAML::Nodes::Scalar)
-        return decode_time_span(node.value)
+        return decode_interval(node.value)
       else
         node.raise "Expected scalar, not #{node.class}"
       end
     end
   end
-end
+end