[i18n] use xgettext compatible function format for plural

Signed-off-by: R4SAS <r4sas@i2pmail.org>

daemon/HTTPServer.cpp

@@ -138,18 +138,18 @@ namespace http {
 		int num;
 
 		if ((num = seconds / 86400) > 0) {
-			s << num << " " << tr("days", num) << ", ";
+			s << num << " " << tr("day", "days", num) << ", ";
 			seconds -= num * 86400;
 		}
 		if ((num = seconds / 3600) > 0) {
-			s << num << " " << tr("hours", num) << ", ";
+			s << num << " " << tr("hour", "hours", num) << ", ";
 			seconds -= num * 3600;
 		}
 		if ((num = seconds / 60) > 0) {
-			s << num << " " << tr("minutes", num) << ", ";
+			s << num << " " << tr("minute", "minutes", num) << ", ";
 			seconds -= num * 60;
 		}
-		s << seconds << " " << tr("seconds", seconds);
+		s << seconds << " " << tr("second", "seconds", seconds);
 	}
 
 	static void ShowTraffic (std::stringstream& s, uint64_t bytes)

i18n/English.cpp

@@ -13,6 +13,7 @@
 #include "I18N.h"
 
 // English localization file
+// This is an example translation file without strings in it.
 
 namespace i2p
 {
@@ -33,10 +34,6 @@ namespace english // language
 
 	static std::map<std::string, std::vector<std::string>> plurals
 	{
-		{"days",    {"day", "days"}},
-		{"hours",   {"hour", "hours"}},
-		{"minutes", {"minute", "minutes"}},
-		{"seconds", {"second", "seconds"}},
 		{"", {"", ""}},
 	};
 

i18n/I18N.h

@@ -32,9 +32,9 @@ namespace i18n
 		return i2p::context.GetLanguage ()->GetString (arg);
 	}
 
-	inline std::string translate (const std::string& arg, const int& n)
+	inline std::string translate (const std::string& arg, const std::string& arg2, const int& n)
 	{
-		return i2p::context.GetLanguage ()->GetPlural (arg, n);
+		return i2p::context.GetLanguage ()->GetPlural (arg, arg2, n);
 	}
 } // i18n
 } // i2p

i18n/I18N_langs.h

@@ -35,12 +35,12 @@ namespace i18n
 				}
 			}
 
-			std::string GetPlural (const std::string& arg, const int& n) const
+			std::string GetPlural (const std::string& arg, const std::string& arg2, const int& n) const
 			{
-				const auto it = m_Plurals.find(arg);
-				if (it == m_Plurals.end())
+				const auto it = m_Plurals.find(arg2);
+				if (it == m_Plurals.end()) // not found, fallback to english
 				{
-					return arg;
+					return n == 1 ? arg : arg2;
 				}
 				else
 				{