Fix FTBFS on newer pqxx versions

(cherry picked from commit da48979ab0)

kexi/kexidb/drivers/pqxx/pqxxdriver.cpp

@@ -133,8 +133,10 @@ bool pqxxSqlDriver::isSystemDatabaseName( const TQString& n ) const
 //
 TQString pqxxSqlDriver::escapeString( const TQString& str) const
 {
+    TQString escaped = str;
+    escaped.replace("'", "''");
     return TQString::fromLatin1("'")
-    	+ TQString::fromAscii( pqxx::sqlesc(std::string(str.utf8())).c_str() )
+    	+ escaped
     	+ TQString::fromLatin1("'");
 }
 
@@ -142,8 +144,10 @@ TQString pqxxSqlDriver::escapeString( const TQString& str) const
 //
 TQCString pqxxSqlDriver::escapeString( const TQCString& str) const
 {
+    TQString escaped = str;
+    escaped.replace("'", "''");
     return TQCString("'")
-    	+ TQCString( pqxx::sqlesc(TQString(str).ascii()).c_str() )
+    	+ TQCString( escaped.ascii() )
     	+ TQCString("'");
 }