Remove flat for hue_change

It causes bad rendering in adreno 306 in android 5.0

data/shaders/sp_alpha_test.frag

@@ -1,4 +1,4 @@
-flat in float hue_change;
+in float hue_change;
 
 in vec4 color;
 in vec3 normal;

data/shaders/sp_ghost.frag

@@ -1,6 +1,6 @@
 uniform float custom_alpha;
 
-flat in float hue_change;
+in float hue_change;
 
 in vec2 uv;
 in vec4 color;

data/shaders/sp_grass.frag

@@ -1,4 +1,4 @@
-flat in float hue_change;
+in float hue_change;
 
 in vec3 normal;
 in vec2 uv;

data/shaders/sp_grass_pass.vert

@@ -25,7 +25,7 @@ layout(location = 12) in ivec2 i_misc_data;
 
 out vec3 normal;
 out vec2 uv;
-flat out float hue_change;
+out float hue_change;
 
 void main()
 {

data/shaders/sp_normal_map.frag

@@ -1,4 +1,4 @@
-flat in float hue_change;
+in float hue_change;
 
 in vec4 color;
 in vec2 uv;

data/shaders/sp_pass.vert

@@ -38,7 +38,7 @@ out vec2 uv_two;
 out vec4 color;
 out vec4 world_position;
 out float camdist;
-flat out float hue_change;
+out float hue_change;
 
 void main()
 {

data/shaders/sp_skinning.vert

@@ -44,7 +44,7 @@ out vec2 uv;
 out vec2 uv_two;
 out vec4 color;
 out float camdist;
-flat out float hue_change;
+out float hue_change;
 
 void main()
 {

data/shaders/sp_solid.frag

@@ -1,4 +1,4 @@
-flat in float hue_change;
+in float hue_change;
 
 in vec4 color;
 in vec3 normal;