Simplify code by removing usage of String.format() for log messages.

From http://www.baeldung.com/slf4j-log-exceptions
%
In presence of multiple parameters, if the last argument in a logging
statement is an exception, then SLF4J will presume that the user wants
the last argument to be treated as an exception instead of a simple
parameter.
%

No functional changes.

Author: php-coder

src/main/java/ru/mystamps/web/controller/ErrorController.java

@@ -67,12 +67,12 @@ public void internalError(
 		// TODO: log to database (with *.status_code, *.message, *.servlet_name and user details)
 
 		if (page != null && !Url.INTERNAL_ERROR_PAGE.equals(page)) {
-			String msg = String.format(
-				"Exception '%s' occurred at page %s",
+			LOG.error(
+				"Exception '{}' occurred on page {}",
 				getNameOrAsIs(exceptionType),
-				page
+				page,
+				exception
 			);
-			LOG.error(msg, exception);
 		}
 	}
 

src/main/java/ru/mystamps/web/service/ImageServiceImpl.java

@@ -166,10 +166,7 @@ private ImageDto createPreview(ImageInfoDto previewInfo, byte[] image) {
 			return new DbImageDto("jpeg", preview);
 
 		} catch (CreateImagePreviewException | ImagePersistenceException ex) {
-			log.warn(
-				String.format("Image #%d: couldn't create/save preview", previewInfo.getId()),
-				ex
-			);
+			log.warn("Image #{}: couldn't create/save preview", previewInfo.getId(), ex);
 			return null;
 		}
 	}