simplify test after PNG compression

Author: arnaudroques

src/test/java/net/sourceforge/plantuml/servlet/TestMultipageUml.java

@@ -30,9 +30,8 @@ public void testPngIndexPage() throws IOException {
         );
         // Get the image and verify its size
         byte[] inMemoryImage = getContentAsBytes(conn);
-        int diagramLen = inMemoryImage.length;  // 7525
-        Assertions.assertTrue(diagramLen > 6000);
-        Assertions.assertTrue(diagramLen < 9000);
+        int diagramLen = inMemoryImage.length;
+        Assertions.assertTrue(diagramLen > 100);
     }
 
     /**
@@ -52,9 +51,8 @@ public void testPngIndexPageNoIndex() throws IOException {
         );
         // Get the image and verify its size
         byte[] inMemoryImage = getContentAsBytes(conn);
-        int diagramLen = inMemoryImage.length;  // 4196
-        Assertions.assertTrue(diagramLen > 3000);
-        Assertions.assertTrue(diagramLen < 5000);
+        int diagramLen = inMemoryImage.length;
+        Assertions.assertTrue(diagramLen > 100);
     }
 
     /**

src/test/java/net/sourceforge/plantuml/servlet/TestOldProxy.java

@@ -32,8 +32,7 @@ public void testDefaultProxy() throws IOException {
         // Get the image and verify its size (~2000 bytes)
         byte[] inMemoryImage = getContentAsBytes(conn);
         int diagramLen = inMemoryImage.length;
-        Assertions.assertTrue(diagramLen > 2000);
-        Assertions.assertTrue(diagramLen < 3000);
+        Assertions.assertTrue(diagramLen > 100);
     }
 
     /**

src/test/java/net/sourceforge/plantuml/servlet/TestProxy.java

@@ -32,8 +32,7 @@ public void testDefaultProxy() throws IOException {
         // Get the image and verify its size (~2000 bytes)
         byte[] inMemoryImage = getContentAsBytes(conn);
         int diagramLen = inMemoryImage.length;
-        Assertions.assertTrue(diagramLen > 2000);
-        Assertions.assertTrue(diagramLen < 3000);
+        Assertions.assertTrue(diagramLen > 100);
     }
 
     /**