decreases ttl time to 15 minutes (#35)

Co-authored-by: JP Engstrom <[email protected]>

cantaloupe.properties

@@ -472,7 +472,7 @@ cache.server.source = FilesystemCache
 
 # Amount of time source cache content remains valid. Set to blank or 0
 # for forever.
-cache.server.source.ttl_seconds = 86400 
+cache.server.source.ttl_seconds = 900
 
 # Enables the derivative (processed image) cache.
 cache.server.derivative.enabled = true
@@ -483,7 +483,7 @@ cache.server.derivative = S3Cache
 
 # Amount of time derivative cache content remains valid. Set to blank or 0
 # for forever.
-cache.server.derivative.ttl_seconds = 86400 
+cache.server.derivative.ttl_seconds = 900 
 
 # Whether to use the Java heap as a "level 1" cache for image infos, either
 # independently or in front of a "level 2" derivative cache (if enabled).